Zong not starting again

[Pabesco]

Hello to All. Seasons greetings. My zong started acting strange yesterday with a few backfires now today it ran fine then cut off this afternoon and now won't start. I thought it was the CDI again So I replaced it and no difference. I checked the air filter and changed that after oiling it. I checked what I could with the carb and its very clean and no clogs. I took the spark plug out and checked the compression by placing my finger over the hole and no matter how hard I press, my finger gets blown away as soon as it cranks. I left the plug connected to the coil and cranked and noticed the spark is not bright at all and sometimes not there at all. I will get a plug tomorrow but would like to know if that's not the problem where else should I be checking to get my bike running again.
Thanks and have a great evening.

[SpudRider]

If the spark plug is not firing, or you are getting a weak spark, the problem is electrical. Since you already replaced the CDI unit, you know the CDI unit isn't causing the problem. You were wise to replace the spark plug. If a new spark plug doesn't rectify the problem, you either have a bad ignition coil, or a bad stator/pickup coil. ;)

Spud :)

[Pabesco]

When I ordered the Cdi units from china I ordered the pickup coil and electrical coil as well as a new magneto so I think I have everything I will need to test properly. Thanks spud. I'll let you know how it goes after changing the plug tomorrow.

[Weldangrind]

It sure is nice to have parts like those on hand for troubleshooting. Was your purchase from China smooth?

[Pabesco]

Pretty much. Just took a long time for them to get the parts from their suppliers. After they got them they were shipped right away and DHL had them in Miami in 3 days. So the experience was good. I also rechecked with zongshen ameri a on their parts and they seemed to have dropped their prices on a lot of items. Here is a quote from the guy there named Nestor.

> Cdi $ 24.00
> Stator/magneto/Pickup coil $ 27.00
> Rectifier $ 16.00
> Front brakes We don't have in stock
> Air filter $ 6.00
> Rear wheel hub We dont't have in stock
> Clutch cable $ 14.00
> Speedometer cable $ 12.00
> Rear light lens We don't have in stock

Thanks!!!
Nestor

[FastDoc]

I had a Zong 250 with a weak spark. I fixed it with a new stator and pickup coil. It still would not run and the problem turned out to be poor compression from a cracked head. Your compression is good so the problem may be the stator and/or coil.

[Pabesco]

I changed the spark plug and the bike is running now. It somehow doesn't feel exactly as it did before with initial take off. Might just be me. Not sure yet. I will also take it to a machenic friend of mine to check the compression as I did t order the compression tester yet.
Thanks to all and I'll be sure to post any changes and compression results

[SpudRider]

I won't be surprised if the new spark plug fixes the problem. Spark plugs are inexpensive, and you should change them regularly. ;)

Spud :)

[Pabesco]

Thanks once again guys. I also fond the oil leak. It was the timing chain cover bolt slack

[FastDoc]

I'm not worried about the compression so much.

The 250 Zongs seem to have a lot of problems. The 200 Zongs are different animals and very robust.

[Pabesco]

Thanks doc, had me scared there for a minute. I'll still check it just to be sure. I also ordered a compression tester. I like to have my own tools and learn how to troubleshoot and repair myself.

[FastDoc]

It's a good tool to have. Even though I'm sure it's not a problem now its good to have a basline for future comparison.

There's a good tutorial on www.dansmc.com if you need it. :D

[Pabesco]

Great toturial thanks

[FastDoc]

Brother Dan rocks. :wink:

[Pabesco]

Bike ran ok for a few days, I was right when I thought it just didn't feel right. Now lastnight it cut off and took about 5 tries to get it started then it backfired a few times and I had to throttle it sort of hard to just get home. This morning it started fine and ran well for about 10 minutes then cut off and took a while to start again and ran sloppy so I parked it. Exhaust also smells a bit different but I don't know how to discribe the difference In smell.

[SpudRider]

Now it's time to test the resistance readings from the ignition coil, stator, and pickup coil. If you don't have a digital multimeter, buy one. With the engine cold, test for the proper resistance values specified in the TW200 Service Manual. The service manual is available for download in the Zong Sticky. ;)

Spud :)

[Pabesco]

Hey spud. I don't have a tester but I had all of the parts so I changed them one at a time and checked to see if the bike would start. So far I have changed the firing coil (that connects to spark plug) then I changed the Cdi again. Then I changed the rectifier (black box under seat). none of this worked so i'm about to change the stator (magneto) to see if that's the problem. If it still doesn't start, where should I go from there?

[SpudRider]

Hey spud. I don't have a tester but I had all of the parts so I changed them one at a time and checked to see if the bike would start. So far I have changed the firing coil (that connects to spark plug) then I changed the Cdi again. Then I changed the rectifier (black box under seat). none of this worked so i'm about to change the stator (magneto) to see if that's the problem. If it still doesn't start, where should I go from there?
The stator and pickup coil (sold as a pair) and the only two components you haven't changed. The regulator/rectifier won't cause the problems you have observed. ;) You might have a loose connection somewhere. Check to see if the connectors from the stator and pickup coil are secure. These connections are located in the small rubber boot near the carburetor. Examine these connections and check all the wiring for abrasions before you change the stator/pickup coil. Also, make sure you have a good ground connection for the motorcycle. Did you check the connections in the spark plug boot?

Spud :)

[Pabesco]

I changed the stator as well but still not starting. I'll get another spark plug ASAP and try that also. I don't know what else to check. Guess ill be doing some reading over the holidays.
MERRY CHRISTMAS TO ALL AND PLEASE EVERYONE.... REMEMBER THE REASON FOR THE SEASON.
ENJOY.

[SpudRider]

Did you install a new pickup coil? If so, you replaced everything which sends electricity to the spark plug.

Spud :)

[Pabesco]

Yes a new pickup coil came with the new stator so I changed that as well. The plug boot is also new.
Whatever the problem is or maybe was now, it might have fouled the plug again so I'll get another plug and check to see if this corrects the problem.

[Pabesco]

I will be sure to go over the whole wire harness tomorrow to see if there is anything lose or frayed.
Thanks and I'll be sure to update as I go along. This is a great learning g experience for me.

[SpudRider]

Check to make sure the large ground wire is securely bolted to the engine frame behind the cylinder. If you want to do your own electrical work, you really do need to acquire a digital multimeter; it doesn't have to be an expensive one. Can you get someone to loan you a digital multimeter? Even a test light would help you confirm your bike's electrical grounding system is in good shape. ;)

Spud :)

[DannyPizdetz]

I had a similar problem and it wasn't the ground behind the engine mount it was the ground at the battery box. Tightened it up and ran like a champ...until the tire went flat. I still need to loctite that bolt down so that it doesn't work loose again.

[Pabesco]

I do have a test light and I ordered a multimeter as well. I didn't get a chance to do any work on it today, all my time was taken up with the 7 kids. Had the best day ever. I'll check all of these things starting first thing tomorrow morning and will post results ASAP. Thanks for all the great suggestions and help guys. Sometimes the simplest things we don't think of. I really did t check the ground to the frame or to the battery and I should have checked these before anything g else.
Thanks again guys. Have a great evening. And on e again MERRY CHRISTMAS.

[TheSkipper]

Have you tryed bypassing your killswitches? I highly doubt that they are the problem though. I'm almost postive it is the stator and pick coil. Its about the only thing that can produce a intermittent problem like you are describe.

[SpudRider]

The Zong's kill switch operates by grounding the output from the CDI unit. Therefore, a defective kill switch won't cause ignition problems for the Zong; it will only cause a problem when trying to kill the engine. ;)

Spud :)

[Pabesco]

I changed everything g I could think of including the spark plug and still not starting. I check all of the connections of the harness and can't seem to find any problems. I will ask a friend to check it for me he's a machenic. I can't think of anything else to do.

[SpudRider]

You said you had a weak spark. Is that still the case? You might have additional problems with either fuel, air, or compression. Have you checked the valve lash recently? Please do let us know what your mechanic friend discovers.

Spud :)

[Pabesco]

The valves were checked again today and they are fine. I'll keep posting
Thanks

[Pabesco]

Mechanic scheduled to arrive at 6 today. I checked the fire again and it now seems to be pretty strong. I scraped a bit of the paint from the head and grounded the plug there and the spark looks pretty good now. I went a step further and touched the plug while cranking and got a pretty good shock. Now I'm thinking along the lines of it being a fuel problem now. I will pour a bit of gas directly into the cylinder and replace plug and tryto start it right after recharging the battery. If it runs then cuts off then it's a carb issue. I will post ASAP.

[Wild_Alaskan]

you can also try spraying some aresol starting fluid in the intake. probably a little easier to do vs taking the spark plug out

[SpudRider]

you can also try spraying some aresol starting fluid in the intake. probably a little easier to do vs taking the spark plug out
I wouldn't pour fuel into the cylinder! 8O Fuel is supposed to be atomized, and very little fuel causes a large amount of combustion. You could easily damage your engine by pouring gasoline into the spark plug hole. :?

I suggust you have the mechanic examine the carburetor, and make sure the fuel system is operating properly before you attempt to bypass it. If you feel you must introduce fuel, I strongly suggest you follow the advice of the Wild Alaskan, and spray some aerosol starting fluid near the intake of the carburetor. ;)

Spud :)

[Pabesco]

Will do. Thanks guys. I was following the advice found in dans online motorcycle course that was suggested to use as a reference. Glad I didn't try it yet.

[SpudRider]

Will do. Thanks guys. I was following the advice found in dans online motorcycle course that was suggested to use as a reference. Glad I didn't try it yet.
I searched Brother Dan's website and found the following information.

http://www.dansmc.com/starter.htm

"When you rebuild an engine all the parts are new and rough and don't really know each other very well. Because of this, a new engine may be hard to start for the first time. With a fire extinguisher close by, try a small squirt of gas, from an eye dropper, down the spark plug hole. Reinstall the spark plug and it should start. You can use starting fluid, but you need to be very careful and NOT use too much. Same with gas. Just a small squirt. If it doesn't start, find out why. Don't keep pouring more gas or starting fluid down the engine. If you do, a stray spark could end up blowing the exhaust pipe off or setting fire to the engine!"

This information applies to a rebuilt engine with all new parts. However, the procedure is still dangerous. :? I suggest you examine the fuel system and look for problems. Even if you get the bike started using the method described above, the bike won't run for long if you don't fix the underlying problem. ;)

Spud :)

[Pabesco]

I do agree. The mechanic was a no show so i tried it using a bit of starter fluid and it didn't work. But I found that the plug when removed had black smoke on it. I tried cranking for about 10 seconds at a time for four times then removed the plug and it was covered with black smoke residue. Any ideas.

[Wild_Alaskan]

i would clean the carb, Its best to remove the carb and clean each part individually, but if you are feeling lazy, or are intimidated by doing this, you can remove the gas tank unscrew the top of the carb and remove the slide and spray carb cleaner down through the main jet until it starts flowing out the over flow tube of the carb. also spray it down any other holes you can see from this perspective. there will likely be a small hole towards the engine that is for the idle jet, spray it well.

reassemble, make sure the slide is in correctly, twist the throttle when done to make sure it feels normal. pull the choke and run the e start while twisting the throttle between closed and quarter throttle. there will be alot of carb cleaner in the bowl, the motor can burn it just fine if the choke is on (and will run it through the idle passages) . after a bit it will get replaced by gas and everything should return to normal.

[FastDoc]

If you are feeling lazy, or are intimidated by doing this, you can remove the gas tank unscrew the top of the carb and remove the slide and spray carb cleaner down through the main jet until it starts flowing out the over flow tube of the carb. also spray it down any other holes you can see from this perspective. there will likely be a small hole towards the engine that is for the idle jet, spray it well.

Great shortcut, WA. I'll have to remember that one. :wink:

[Pabesco]

Definitely not lazy and more than willing to learn as much as I can. I wi REMO e the carb tomorrow and clean it properly. I will remove all jets and clean all holes. Is there a specific type carb cleaner I should be using?

[Weldangrind]

I just use whatever aerosol carb cleaner I find at the parts store. Please wear eye protection. Your seven kids will thank you.

[Pabesco]

Lol. Will do. Just removed carb and will start taking apart tonight so I can clean it in the morning.
Thanks guys.

[SpudRider]

Definitely not lazy and more than willing to learn as much as I can. I wi REMO e the carb tomorrow and clean it properly. I will remove all jets and clean all holes. Is there a specific type carb cleaner I should be using?
Here's a link to the TW200 forum for a thread called "Lazy Man's Teikei (TK) Carb Cleaning."

http://tw200forum.com/index.php?/topic/866-lazy-mans-teikei-tk-carb-cleaning/

Here's a link to the TW200 forum for a thread called "TK Carb Photos and Parts Identification."

http://tw200forum.com/index.php?/topic/937-tk-carb-photos-and-parts-identification/

I suggest you read these threads before you disassemble the Teikei carburetor of your Zong. I also suggest you purchase a spare, Teikei carburetor from Zongshen America (ZA). I bought a complete, spare carburetor from ZA years ago at a very reasonable price. ;) If you have a spare carburetor you can swap it out the same way you swap out a spare CDI unit. The spare carburetor will also provide spare parts, should you need them. :)

Spud :)

[Pabesco]

I already took the carb out. Removed all parts that could be. Used the carb spray and cleaned the entire carb. All rubber parts were safely put aside prior to spraying. Carb reassembled and reinstalled. Tried to start and it didn't. Battery was sort of low so it's charging g now. I didn't see the links you sent to me prior to doing all of this spud. I'll check them now and hopefully I did everything right. Thanks and ill post after reading

[Wild_Alaskan]

make sure gas valve was returned to on, and also try loosening the carb drain screw and make sure you get a constant flow to make sure there is no blockage and fuel is getting to the carb. i've had a float needle gum up just enought the bowl would fill in about 10 mins and give me hours of trouble shooting grief.

[SpudRider]

I suggest you turn off the fuel petcock (switch). Then remove the fuel line from the carburetor, open the fuel petcock (switch), and verify fuel is flowing from the gas tank. If fuel is flowing from the gas tank, reattach the fuel line to the carburetor. Then open the fuel petcock (switch), and wait a few minutes for the fuel to fill the carburetor float bowl. Then drain the float bowl, and verify fuel exits out the drain hose.

Spud :)

[TCCKSR]

verify your carb float is not stuck up constantly flooding your motor too while you do your carb testing.

[Pabesco]

I checked the tank and float bowl for gas flow and nothing seems to be clogged. I did check the float while I had the carb out and it wasn't sticking or had any type of resistance moving.
The mechanic still hasn't shown up so I have to move to plan B. the compression tester should be here in a few days but I really don't think that's the problem. But reading dans manual it seems you might be fooled thinking you have great compression when in fact you don't. I'll recheck that. Also I will recheck the fire from the carb to make sure I have enough spark. Seems that it's supposed to be a really strong highly noticible spark.
I got some starter fluid and I will try to spray a bit behind the air filter so it would be a vapor entering the engine instead of liquid. I already checked the valve lash and they are both set to spec. I checked the timing and it seems to be right (timi g chain is very very tight). I didn't see the dis ribed "T" mark on the roter so I just set the piston TDC and checked the mark on the cam gear and it looks right.
I'll keep reading and troubleshooting until my bike runs again.
Thanks guys. Great ideas and I check all as I go along.

[66Sprint]

Please check that the rotor key is in place and not sheared

[SpudRider]

Are you talking about the woodruff key which holds the flywheel to the crankshaft, Steve? :?:

Spud :)

[66Sprint]

Yes...a cracked or bent key can change the timing a few degrees and the rotor MAY not stay in one position so it can "wander".... overheating is a common symptom and produces an odd ehaust smell (Cooking aluminum as the piston "holes")
The key doesn't actually "hold" the rotor (the taper does), but it does "index" it for timing purposes....
His rotor may just be "off" enough that he can't see the timing mark when close to TDC on the compression stroke

[SpudRider]

Thanks for the good tip, Steve. :)

I have rebuilt the top end of my Zong's engine twice. In both instances I removed the flywheel in order to replace the timing chain. I have twice inspected my Zong's woodruff key, and it is very substantial. Therefore, I doubt the woodruff key is causing a problem. However, if the left crankcase cover is removed, one could easily check for this condition by trying to twist the flywheel on the crankshaft, checking for looseness. ;)

Spud :)

[66Sprint]

The times we have found this problem did not have to do with how substantial the key was....It concerned how tightly it sat in its cuts....(and this problem was found mostly on the GY-6 scooter engines)...each time you rev suddenly or let off the throttle quickly, the mass off the rotor attempts to remain at the speed it was rotating, while the crank speed suddenly accelerates or decelerates relative to it... Theoretically, the taper should hold/bind them together, but any dust, grit, oil, or a slightly "off" taper cut, can prevent this interlock... As does a loose retaining nut ot bolt....and the rotor literally hammers at the loose key, ultimately shearing it or deforming it enough to alter the timing very slightly....
While I don't think this is the likeliest cause of the problem, I just thought it should be one more thing to check......
I recommend spraying carb cleaner on/in both sides of the tapers while apart to prevent any doubts as to the accuracy/quality of the "bind".... If the rotor can shift/wobble at all, there is a possibility it could damage the pick-up or internal coils....we actually had the trigger "button" tear the windings out of the pick-up on a customer's quad due to his improper install of the rotor.....

[SpudRider]

As always, thank you for posting the excellent information, Steve. We are very glad you joined us on these forums. :D

Spud :)

[Pabesco]

I will have to do some more reading to see exactly what you guys are referring to. I did experience, as mentioned early in this post, that there was a difference In smell. I will remove the left crank case cover again and recheck everything. I didn't know there was something on the rotor that could be shered off. Any instructions as to how to check this or what to look for would be greatly appreciated.
Thanks guys.

[66Sprint]

Not ON the rotor, the key indexes the rotor to the crankshaft ... It might be able to be seen with a flashlight if you remove the nut or bolt in the center of the rotor....

However, before you go there, check the intake manifold "boot" for air leaks/cracking/etc.....These can also cause a lean condition that can change the exhaust smell, cause hard-starting, etc........

[SpudRider]

I agree with Steve. ;) I would concentrate on troubleshooting the carburetor before I pulled the left crankcase cover to inspect the flywheel.

However, if you wish to examine the flywheel after you drain the motor oil, the process should be simple. After removing the left crankcase cover, you can merely try twisting the flywheel on the crankshaft to see if the woodruff key has failed. You cannot examine the Zong's woodruff key by merely removing the bolt at the end of the crankshaft. ;)

Spud :)

[Wild_Alaskan]

here is a video on removing the flywheel

http://youtu.be/j_w8nlq0Vzg

if you dont have a flywheel holder you can usually get the nut off by jaming the drive gear with an aluminum or copper washer, or if the engine is in the bike putting it in 5th gear and having someone push the rear brake.

you probably will need the pulling tool though


have you gotten no reaction from spraying starting fluid down the throat of the carb? Ive seen motors with almost no compression at least fire a couple times on starting fluid. It is extremely easy to ignite.

[66Sprint]

Thanks Spud.....I wasn't sure if the machined cut the key fits in was all the way to the end.....Hence the "might be able".... Understand, that my experiences are mostly with similar circumstances on the "Big 4" (mostly Hondas) and some with the little GY-6 49cc scooter engines (and their up to 80cc "kit" mods)....
I'm just suggesting from similar symptoms and general mechanical eperience..... I WILL be wrong sometimes....maybe even often until I learn more about the Chinese engine versions....
I'm learning from you guys as we go as well, so PLEASE don't hesitate to correct me...It speeds up the learning process..... :D Steve

[SpudRider]

I really don't think anything is wrong with the woodruff key. ;) The Zong's engine is a faithful copy of the currently produced, Yamaha TW200 engine. I have never heard of anyone having this problem with the TW200. Also, I have removed my flywheel twice to replace my cam timing chain; the woodruff key was very robust, and well secured in both instances.

I strongly encourage you to make sure your carburetor is working properly. Then I encourage you to test your electrical components with a digital multimeter, as specified in the TW200 Service Manual. After you do all those things, I am sure you will discover the problem. ;)

Spud :)

[SpudRider]

Thanks Spud.....I wasn't sure if the machined cut the key fits in was all the way to the end.....Hence the "might be able".... Understand, that my experiences are mostly with similar circumstances on the "Big 4" (mostly Hondas) and some with the little GY-6 49cc scooter engines (and their up to 80cc "kit" mods)....
I'm just suggesting from similar symptoms and general mechanical eperience..... I WILL be wrong sometimes....maybe even often until I learn more about the Chinese engine versions....
I'm learning from you guys as we go as well, so PLEASE don't hesitate to correct me...It speeds up the learning process..... :D Steve
As always, we appreciate your thoughtful input, Steve. Thank you for your willingness to help. :)

Spud :)

[Pabesco]

Thanks guys for the great advice. I will be checking he carb again today. I'm taking some time out to make sure I recheck it properly. Where is the best place to spray a small amount of starter fluid with the carb attached? If I'm correct it would be behind the air filter with the filter cover removed. If this is incorrect please let me know.
Once again thanks guys. The digital multimeter and compression tester are supposed to be delivered by Saturday. Are there any other tools or devices I should really have on hand to work on my bike in the future?
I have ratchet sets and other mechanic tools but if there are others I need to get please let me know and I will order them right away
Thanks once again

[SpudRider]

Thanks guys for the great advice. I will be checking he carb again today. I'm taking some time out to make sure I recheck it properly. Where is the best place to spray a small amount of starter fluid with the carb attached? If I'm correct it would be behind the air filter with the filter cover removed. If this is incorrect please let me know.
Once again thanks guys. The digital multimeter and compression tester are supposed to be delivered by Saturday. Are there any other tools or devices I should really have on hand to work on my bike in the future?
I have ratchet sets and other mechanic tools but if there are others I need to get please let me know and I will order them right away
Thanks once again
Remove the air filter cover and the foam air filter. Look inside the air box, and you will see the opening which attaches to the carburetor. Spray the aerosol starter fluid into that opening. ;) It appears you now have the tools you need. :)

Spud :)

[Pabesco]

Good evening to all. Once again thanks for all the much needed help. The mechanic finally showed up and checked the bike. Here are the findings
Carb no problem
Compression no problem
When he removed the plug and checked the spark he discovered the spark was too weak to ignite the gas. He poured a bit of gas into a small can cover and placed the plug right next to it and cranked and it didn't even light the gas. He will return tomorrow to check where the problem is coming from. My multi tester will be here tomorrow too but the mechanic will bring his tester and compression tester as well. I will be sure to post any progress or changes as I go.
If anyone experienced this before please let me know where to check.
The following parts were changed
Pickup coil
Firing coil
Cdi
Rectifier
Magneto
Thanks guys.

[Pabesco]

I am also too g to remove the ground line clean it and the part of the engine it connects to so I can be sure I have a very proper ground.

[SpudRider]

You are wise to clean the ground connection. ;) Also, check your electrical grounding by setting your digital multimeter for "continuity." The connect one lead to the positive terminal of the battery, and probe the frame with the other connector.

The resistance readings for all the electrical components are listed in the TW200 Service Manual. ;)

Spud :)

[Pabesco]

I checked the ground to the engine and its very clean and the bolt holding the cable is very tight. I checked for ground at different parts of the cngine and frame using a circuit tester and didnt find any problems. I will check the resistance on each component tonight or tomorrow morning after reading the stats on the service manual.
Thanks

[Pabesco]

Good afternoon to all. I checked the component as discribed in the tw200 service manual and here are the results.

Plug cap 10.38kohms OK
secondary coil 6.56kohms OK
primary coil tested 0.7 (supposed to be 0.18-0.28)
Pickup coil 836 ohms OK
Source coil 702 ohms OK

The one that tested with a difference from the manual was the primary coil. Is the difference letting me know that the coil is faulty? It is a new coil and the old one tests exactly the same. If it is faulty then they are both faulty and could this have been caused by installing a new ignition coil with a faulty magneto?
I tested the old magneto outside of the motor and it didn't register on the meter at all. The new one inside the motor tested with the above results. I'm not sure if its supposed to be tested outside the motor with the same results if so then the old magneto is definitely faulty and I will discard it.
Hope to hear from you experts ASAP.
Glad to be learning so much by working on it myself but I really need to get it running again.
Thanks guys and have a great day.

[SpudRider]

Good afternoon to all. I checked the component as discribed in the tw200 service manual and here are the results.

Plug cap 10.38kohms OK
secondary coil 6.56kohms OK
primary coil tested 0.7 (supposed to be 0.18-0.28)
Pickup coil 836 ohms OK
Source coil 702 ohms OK

The one that tested with a difference from the manual was the primary coil. Is the difference letting me know that the coil is faulty? It is a new coil and the old one tests exactly the same. If it is faulty then they are both faulty and could this have been caused by installing a new ignition coil with a faulty magneto?...
For the ignition coil, the Yamaha XT225 Service Manual lists the following values.

Primary Coil: 0.56 to 0.84 Ohms
Secondary Coil: 5.68K to 8.52K Ohms

I have two ignition coils for my Zong; both primary coils measure at 0.60 Ohms. Therefore, I think your ignition coil is in good condition. All of the other test readings are also good. :)
...I tested the old magneto outside of the motor and it didn't register on the meter at all. The new one inside the motor tested with the above results. I'm not sure if its supposed to be tested outside the motor with the same results if so then the old magneto is definitely faulty and I will discard it...
The resistance of both the stator and pickup coil should always be measured when the engine is cold. It doesn't make any difference if the components are inside the engine, or outside the engine, when the resistance values are measured.

The resistance values for your new stator and pickup coil are good. Your old stator and pickup coil should have similar resistance values; since they do not, the old components are damaged. ;)

Since the entire electrical system shows proper resistance values, I suspect your replacement CDI unit is bad. :( I have read reports a bad stator/pickup coil can damage a CDI unit; however, I don't know if this is true. Nevertheless, whether the replacement CDI unit was bad when you installed it, or it was damaged by a bad stator/pickup coil, I think the CDI unit is now your problem.

Testing the output from the CDI unit is not reliable. Therefore, I suggest you install another CDI unit, and see if the problem disappears. For this reason it's always good to have several, spare CDI units on hand. If you don't have a second, spare CDI unit, I suggest you buy one from Zongshen America. You can also try the original, CDI unit you replaced, but I suspect it is bad as well. ;)

Spud :)

[Pabesco]

Sorry to ask but was I supposed to read the service manual for the txt 225 or for the tw200? I thought I was to get the component values from the tw 200 service manual. I don't think I downloaded the services manual for the xt225. I will check the stickey and be sure to download and read. I will discard the old stator but the old pickup coil has good reading so I will keep that. I do have another Cdi and I will try that tomorrow and see if it works. I have all of my fingers and toes crossed hoping that's the problems.
Thanks once again spud for the wealth of knowledge and experience you give to others. Have a great evening.

[SpudRider]

Sorry to ask but was I supposed to read the service manual for the txt 225 or for the tw200? I thought I was to get the component values from the tw 200 service manual...
You were correct. However, when I last tested the electrical components in my Zong, I noticed the difference in the ignition coil, resistance values. Therefore, I believe the XT225 specifications are correct in this one instance. ;)
...I do have another Cdi and I will try that tomorrow and see if it works. I have all of my fingers and toes crossed hoping that's the problems.
Thanks once again spud for the wealth of knowledge and experience you give to others. Have a great evening.
You're welcome. :) All the other electrical components check out. Therefore, if the problem is electrical, it must be the CDI unit. ;)

Spud :)

[Pabesco]

Hey spud hope all is well. I changed the cdi and still not starting. I'm not sure if I tried all of the CDis when the problem started and might have damaged both new ones. I'll order another on Monday. Anything else I should be checking?
Thanks

[Pabesco]

If its not electrical what else should I be checking?

[SpudRider]

An internal combustion engine needs four things to operate.

1) Spark (the electrical system)
2) Fuel (the carburetor)
3) Air (carburetor & air box)
4) Compression

Spud :)

[Pabesco]

Installed new carb. Changed hose from air box to engine. Changed and oiled air filter. Compression seems really good. I received my compression tester but all of the fittings and adapters are too big.. Is the size used 10 or 12? I don't want to order the wrong thing again. I found adapters on eBay. I will find the right size here tomorrow and confirm good compression.
Thanks spud. Good night

[FastDoc]

To Spud's list I add timing.

[Pabesco]

I'll read up on timing again and double check it. I do t see a mark on the bottom section though. I unscrewed both chrome covers and look at both and don't see a mark to set to the piece on the engine. Any suggestions. I will set it to TDC and recheck as bet I could.
Thanks doc. Have a great day

[Weldangrind]

Pabesco, have you tried push starting it?

[Pabesco]

No I havnt tried that. Would it make a difference from cranking with the foot?
If it makes a difference ill definitely try it. I also did some reading and read that sometimes earlier model bikes could lose the magnetism around the rotor area and would need to be demagnetized. I took the crank case cover off again and the pull of the magnet seems ok. Not too strong but I think strong enough.

[SpudRider]

To Spud's list I add timing.
I doubt the timing is off, Doc. The flywheel has a bump on it which passes in front of the pickup coil. Unless the mount has been altered, the pickup coil always remains in the same position. Also, the flywheel is locked to the crankshaft with a woodruff key, so it can't change position either. ;)

Spud :)

[SpudRider]

Pabesco, have you tried push starting it?
The Zong has a kick starter as well as an electric starter, Weld. :)

Spud :)

[SpudRider]

No I havnt tried that. Would it make a difference from cranking with the foot?
If it makes a difference ill definitely try it. I also did some reading and read that sometimes earlier model bikes could lose the magnetism around the rotor area and would need to be demagnetized. I took the crank case cover off again and the pull of the magnet seems ok. Not too strong but I think strong enough.
The flywheel should be magnetized very strongly; it should not be easy to remove the left crankcase cover. However, I have never heard of magnetic problems with the TW200/XT225 flywheel. :?

Spud :)

[SpudRider]

I'll read up on timing again and double check it. I do t see a mark on the bottom section though. I unscrewed both chrome covers and look at both and don't see a mark to set to the piece on the engine. Any suggestions. I will set it to TDC and recheck as bet I could.
Thanks doc. Have a great day
You can't alter the timing unless you modify the mount for the pickup coil, and I certainly don't recommend that procedure. ;)

Spud :)

[katoranger]

If the compression is low a push start in a higher gear may work. 2 strokes become difficult to start with low compression and alot of times will start by pushing, but not with a kick.

With everything else seeming to check out I am really wondering about the compression.

[SpudRider]

Pabesco said he had a weak spark. Since all the resistance readings are good for the electrical system, I still think the problem is a bad CDI unit.

However, if the spark is good, I think bad compression is the next most likely problem. How often do you check the valve lash? What readings do you get for the current valve lash? Has the intake valve been tight the last few times you checked the valve lash. Finally, what is the compression reading for the cylinder?

Spud :)

[katoranger]

It is very possible that he has 2 bad CDIs.

[SpudRider]

It is very possible that he has 2 bad CDIs.
Indeed, especially since the source coil on his stator was bad. However, I think it's highly unlikely he will have three, bad CDI units. ;)

The intake valve recessed into the valve seat on my Zongs original cylinder head. :roll: In fact, the entire valve seat was obliterated. 8O Therefore, intake valve problems, or poor compression are also possible. :(

Spud :)

[Pabesco]

Good evening guys and thanks for all of the great info. The valve lashes are set to spec. I checked them last week. As for push starting I have a nice small hill in front of my property and I will defi items try this. I will order another Cdi on Monday and if this proves to be the problem I will order two additional units to keep on hand. Along with another magneto.
The compression tester I ordered did not come with the size adapter needed to screw into the plug hole so I'm trying to find the right one.
Hopefully it's as simple as the magneto being faulty then caused the cdis to go faulty due to trouble shooting because I think I tried both of the new ones before changing g the magneto. This was the last thing changed so it is possible I damaged both new Cdi units while testing.
I will borrow a compression tester tomorrow and post all results on one page so we can see where we are
Thanks guys and have a great night

[Pabesco]

If it does come to needing a head (with the valves installed) at anytime now or in the future where would I be able to find one? I checked ZA and tbtrends and no luck.

[SpudRider]

If you haven't noticed reduced power output and consistently tight valve clearances, you probably aren't going to need a new cylinder head. However, you can get a used, TW200, or XT200 cylinder head from many places, including eBay. ;)

Spud :)

[Weldangrind]

As for push starting I have a nice small hill in front of my property and I will defi items try this.

If it doesn't start, please don't curse my name as you're pushing your Zong back up the hill. :lol:

[Weldangrind]

If the compression is low a push start in a higher gear may work. 2 strokes become difficult to start with low compression and alot of times will start by pushing, but not with a kick.

With everything else seeming to check out I am really wondering about the compression.

My thoughts exactly. I've push started lots of junk that simply wouldn't kick start.

[Weldangrind]

Pabesco, have you tried push starting it?
The Zong has a kick starter as well as an electric starter, Weld. :)

Spud :)

Just like my trusty TW.

[Weldangrind]

If it does come to needing a head (with the valves installed) at anytime now or in the future where would I be able to find one? I checked ZA and tbtrends and no luck.

Before going down that road, how many km on your bike?

[FastDoc]

To Spud's list I add timing.
I doubt the timing is off, Doc. The flywheel has a bump on it which passes in front of the pickup coil. Unless the mount has been altered, the pickup coil always remains in the same position. Also, the flywheel is locked to the crankshaft with a woodruff key, so it can't change position either. ;)

Spud :)

I wasn't highly suspecting this but mentioned it on general troubleshootiung principle. Also valve timing being off can keep a motor from running. :wink:

[FastDoc]

If the compression is low a push start in a higher gear may work. 2 strokes become difficult to start with low compression and alot of times will start by pushing, but not with a kick.

With everything else seeming to check out I am really wondering about the compression.

My thoughts exactly. I've push started lots of junk that simply wouldn't kick start.

Amen.

Beware the CL bike:

"Kick starter broken but will push start".

[Pabesco]

Tried the push start three times sou des a lot closer to starting g but didn't. I also found it to push the bike in second gear with the clutch lever pulled all the way back. Never had this happen before. Would it be be quad of the new source coil and stator? I have just over 3500 km on the bike. How would I check the valve timing?
Also I rechecked ZA and they do have the cylinder head and everything to go with it. Here's a complete list of the parts I asked them for and the prices


200cc Sierra
Cylinder head $ 95.00
Valves $ 6.00 each
Cam Shaft $ 12.00
Cam Shaft Sleeve $ 14.00
Timing Sprocket $ 16.00
> Cdi $ 24.00
> Stator/magneto/Pickup coil $ 27.00
> Rectifier $ 16.00
> Front brakes We don't have in stock
> Air filter $ 6.00
> Rear wheel hub We dont't have in stock
> Clutch cable $ 14.00
> Speedometer cable $ 12.00
> Rear light lens We don't have in stock
Piston and rings I Don't have in stock
Clutch assembly I Don't have in stock
Valve springs I Don't have in stock
Tapids I Don't have in stock
Valve seals I Don't have in stock
Timing chain $ 10.00
Timing chain tensioner $ 4.50
Timing chain guide $ 3.50
Carburator $ 55.00

Prices Arnt bad

[SpudRider]

A new stator and pickup coil will not make the bike more difficult to push. I wouldn't bother to check the valve timing; I'm sure it is correct. ;)

Indeed, those prices are good. :)

Spud :)

[Wild_Alaskan]

a cold bike will be especially difficult t push when in gear with the clutch pulled, do you have a friend with a quad that could give you a pull?

[Pabesco]

No I don't but I can find a good hill. Some of our hills have almost no traffic at times. I'll see how it goes. The new Cdi abound be here along worth the compression tester adapter by Thursday so I should be able to give all the proper stats by Saturday or might even get it started. I'll be sure to post any results.

[Weldangrind]

When you're trying to start it, pop it into second, not first.

[FastDoc]

Or even third if it skids in second when you pop the clutch. In the dirt I'll use any gear up to 5th depending on my speed. If I stop the bike at the top of the hill I will occasionally bump start rather than kick start it.

[Pabesco]

Thanks guys. I'll let you know how it goes.
Have a great day

[FastDoc]

At the moment it is better to have a non-running Zong in the sunny Bahamas than a running Zong in the snowy Idaho mountains. :wink:

[SpudRider]

At the moment it is better to have a non-running Zong in the sunny Bahamas than a running Zong in the snowy Idaho mountains. :wink:
Rub it it, Bill! :evil:

Spud :lol:

[FastDoc]

:lol:

[Weldangrind]

:lol: , literally!

[Pabesco]

I changed the Cdi and still NOT STARTING. I disconnected the kill switch. I rechecked the valves. I rechecked the resistance on all of the other parts. Iv installed a new carb. New plug. And still not starting. I'm about to give up and look for another type machine. Can't afford to be down this long with no results

[FastDoc]

Please refresh my memory. You are getting spark but weak? You have tried the starting fluid test but no go? I wish you were local to me or one of the other guys I'm sure we could help you out if we had the bike in one of our shops...

[Wild_Alaskan]

I had a wiring harness go bad on my lifan, if you have a wiring diagram you could try testing the ignition related wires. or just buy a new harness

[SpudRider]

Is the problem electrical; do you still have a weak spark? If so, your wiring must be bad. Examine the entire wiring harness, and check for loose connections or bare wires.

Spud :)

[Pabesco]

I did check the entire wiring system and didn't find any loose or frayed wires. I checked all of the harness couplings and found slight COROSION on a few of them but nothing much just a slight green discoloration. I cleaned them up. I will take everything off the bike and chech the entire harness bit by bit to see if I missed anything. Is there a specific test for the ignition switch (key switch)?
I will also check the wiring diagram and see where to test certain spots.
Thanks again guys. I will purchase another machine but I won't sell this one. This will be my educational machine. I will learn everything about this bike. I noticed that a lot of persons here are buying Chinese bikes and most are now not running. I know 4 really good motorcycle mechanics here and spoke with all of them and they all told me the same thing. "If its a Chinese bike just take the bike and all of its parts to the scrap metal shop or the city dump and leave them there".
My beliefe is that if it can be built then it can be repaired. I WILL get this bike running.

[Pabesco]

To you guys that own other bikes (non Chinese) what type bike wod be best for me. I prefer a trail bike over street now. Had too many street bikes when I was younger. I need something that suits me. I'm 6 feet and 240 lbs.
thanks guys

[FastDoc]

XR250. KLX250. DR250. XT250. Assuming you are looking for good simple VERY reliable long lived inexpensive D/S motorcycles.

With all due respect to your mechanic(s) their universal condemnation of Chinese bikes is unwarranted. All can be serviceable, and some, ironically like your Zong, are excellent (usually).

With that said I understand your frustration. Get one of the above and ride your heart out. Fix and enjoy the Zong.

BTW I don't think its the ignition switch. If that was the case there would be no spark.

[Wild_Alaskan]

I like the KTM EXC series of bikes. Some come from the factory street legal, Im not sure if its hard to get bikes legalized in the Bahamas but all EXC bikes come setup with a head light and a tail light minimum. They also last for a really long time, are light weight and powerful, and take very little maintenance.

[Pabesco]

Thank you guys for the info and i will look into these models you listed. In the bahamas you will need front and rear lights in order to get inspection and license for the road. and I agree with what you said. Some people just don't want to take time to get to know new and unfamiliar things and easily condemn. I will keep and enjoy my zong for a very long time. I have ordered alot of parts to keep on hand just Incase. I will also order a cylinder head to keep. I have in stock now a new piston, new Valves. New seals. New rockers. New upper engine (piston area). New gaskets. Rear wheel. Rectifier. Ignition coil. Firing coil. Cdis. Carb. Air filters. Sprockets. Chain.
I get what I can when I find it.
Thanks again

[SpudRider]

Have you been able to push start, or kick start the bike? Have you verified the problem is still electrical?

If the problem is with the electric starter, I suggest you also disassemble, and inspect the starter button. In fact, I suggest you replace the starter button with a good switch, as I did in the following thread.

http://www.chinariders.net/modules.php?name=Forums&file=viewtopic&t=9878

I also suggest you examine the ignition switch. Check to see if the switch is secure, and the top does not wobble. The switch is held together by two, allen head screws in the bottom of the switch. If the screws become loose, the switch will not function properly. In that case, remove the screws, and apply red loctite before you tighten them.

Spud :)

[Pabesco]

Good morning to all. I'm checking all of the wiring and found a loose connection at the ignition switch connector. I temporarily cut the other end off and spliced it together directly. But I discovered something else. I'm using the schematics diagram for the tw200 2001 and newer posted in the stickey and I am aware of the color code difference and was a me to figure it out until I got to the main switch (ignition switch). L/Y going into the switch I'm sure is the B/W coming from the CDI. Now my problem is that according to the schematics I'm supposed to get continuity going across L/Y and L/B and across R and Br. Which colors on the zong do these match up to because on the zong the colors on the connectors are R, B, B/W and G. When I go across the ones I think I'm supposed to get continuity from I only get it on one set.
The lines coming from the main key switch while disconnected from harness With the key switch on I get continuity between R and B. with switch off I get no continuity I get no continuity across any other set with key turned on but When key is turned off I get continuity between G and B/W.
when testing the connector on the harness side I got the following results.
With the key switch on or off I get continuity between B and G. With a resistance reading of 5.1 ohms.
With key turned on or off I get a reading of 910ohns going across B/W and R (tester lead black touching R on connector and tester lead red touching B/W on connector) I don't get the tone on my meter showing continuity across these wires though.
Finally with key swthch on or off I get a reading of 562ohms when black lead of tester is touching B/W and the red lead of tester is touching G.
And with black lead of tester touching B/W and the red lead of tester touching B, I get a reading of 566ohms.
Can anyone confirm if this is correct with a running zong or is there a problem with my key switch?
Thanks guys

[Wild_Alaskan]

dont know specifically about the zong, but generally if it is a four wire switch two of the wires will have continuity when its off (to ground the ignition). and the other two will have continuity when it is on (all other electronics, these wires are usually fatter)

[Weldangrind]

I have a TW, so my wire colours are different from yours. That said, it sounds like your ignition switch is working properly.

Since you get continuity between R and B, my guess is that R comes from the battery and B feeds everything that is powered through the switch, like the starter, the signals, etc.

Since you get continuity between G and B/W with the switch off, my guess is that G is the ground and B/W goes to the CDI.

Rather than trying to find continuity between colours, check the continuity of each of the four ignition wires. Make sure that R has continuity to the battery, B has continuity downstream to the starter switch, G has continuity to ground and B/W has continuity to the CDI (assuming I'm correct in my colour guessing).

[SpudRider]

I will ask a third time. ;) Are you sure your electrical system still has problems? Do you still have a weak, or intermittent spark? Have you been able to push start, or kick start your Zong?

Don't use the TW200 wiring diagram for your Zong. The Zongshen electrical system is different from the TW200 electrical system. Use the Zongshen wiring diagram, which is located on the last page of the Zongshen Service Manual. If you don't have a Zongshen Service Manual, you can find the European version available for download in the Zong Sticky.

http://www.chinariders.net/transfer/spudrider_01-09-2010_123552_LZX200GY-2EC-Service_Manual.pdf

By all means, test your ignition switch. However, as long as the connections are secure, I doubt the ignition switch has internal problems; it is well manufactured, and very robust. Instead, I suggest you follow Weldangrind's advice, and check the continuity of the 4 wires. :) Indeed, check the continuity, and integrity, of all the wires in the electrical system. ;)

Spud :)

[Pabesco]

I rechecked the spark again today and yes it is still very weak. I tried starting it by rolling sown a hill and poping it into second but no luck. I tried it a few times. I will check for continuity the way weldandgrind suggested and post the results. But yes the spark is still very weak. Unless its dark you can Hadley see the spark. I placed the plug close to the engine head after scraping a bit of the paint away to expose the bare metal, and in order to get the spark to jump to the engine I had to hold the plug very close to the engine, like less than a quarter inch away. Any further and the spark would not jump.

[Pabesco]

Is there a test for the source and ignition coil while cranking the bike? Also for the firing coil without the spark plug? Will I be able to put my multimeter across certain leads and crank the bike to see if the right amount of power is being sent to wherever it needs to go?
Thanks guys

[Wild_Alaskan]

That seem like a pretty strong spark to me. usually they are tested by touching the plug to the engine block and then watching the spark jump the gap between the electrode and metal on the spark plug. if you are getting spark that will jump the gap on the plug and then jump another 1/4 inch to the block that should be plenty good.

[Wild_Alaskan]

Sorry if I just missed these posts but did you do a compression test?

Have you investigated the flywheel for tightness/sheared woodruff key?

Did spraying starting fluid directly in to the carb result in no little pops whatsoever?

[SpudRider]

That seem like a pretty strong spark to me. usually they are tested by touching the plug to the engine block and then watching the spark jump the gap between the electrode and metal on the spark plug. if you are getting spark that will jump the gap on the plug and then jump another 1/4 inch to the block that should be plenty good.
Indeed! 8O I don't think you are having any electrical problems.

Spud :)

[SpudRider]

Sorry if I just missed these posts but did you do a compression test?

Have you investigated the flywheel for tightness/sheared woodruff key?

Did spraying starting fluid directly in to the carb result in no little pops whatsoever?
X2. ;)

I strongly doubt the flywheel is loose. However, it won't hurt to check the flywheel after you have done a compression test, and experimented with spraying starting fluid into the carburetor while cranking the engine.

Spud :)

[Pabesco]

How would I spray starter fluid Into the carb. I tried starter fluid directly into the intake with the carb removed and it didn't seem any different. Is it possible to spray fluid into the carb? When the carb is connected I know the float bowl fills up because I can drain it also if I Remove the plug right after trying to start it I can smell gas on the plug. I'm still waiting on a 10mm adapter for my compression tester so I can get an exact reading but if I cover the plug hole with my finger no matter how hard I press I cannot keep it there while cranking the bike. I will do a video tomorrow to try to show the plug spark and hopefully the engine sound will be completely audible.
If I have to check the flywheel what exactly am I supposed to be looking for besides tightness or only this and what should I be looking for on the woodruff? If it is still where it is supposed to be do I remove it and check for ware or damage?
I will do more reading o. Compression but what range should I be looking for when I am able to test it on Tuesday after collecting the adapter?
I did a complete check of the wiring system today and after reviewing g your comments don't think there is a problem with any point in the wiring.
I purchased a new carb and installed it as advised also and checked the mixture setting and it seems to be in the range desired. Is there any other preps needed for a new carb before installing? I also didn't change the main jet as yet I wanted to get it running first.
Thanks to everyone for all of the great suggestions. Great learning experience. Thanks again

[SpudRider]

If you got a brand new carburetor, I'm confident it is in good condition. Therefore, I think you should concentrate on one task at a time, and check the compression before you do anything else.

When checking the compression, use the technique in the following thread.

http://chinariders.net/modules.php?name=Forums&file=viewtopic&t=7807

Leave the kill switch in the "off" position, and make sure you ground the outside electrode of the spark plug. Otherwise, you might damage your new, CDI unit! 8O

Crank the engine with the throttle wide open, otherwise you will not get the proper compression reading. Check the ambient air temperature, and let us kow how warm the day was when you conducted the compression test. Also, post a photograph of your compression tester, so we know what type it is.

Finally, conduct the compression test at least three times. Record the results, and report to us the readings. I'm not going to tell you what reading you should get. I want you to tell us each of the three compression readings you obtain. ;)

Spud :)

[Pabesco]

http://i1271.photobucket.com/albums/jj635/Pabesco/08AE000C-86C1-4905-BF36-B20262481360-755-0000001C248D0E08_zpsff5990ee.jpg

[Pabesco]

I will follow your directions and thank you for the info. I had no idea I could damage the Cdi if the plug is not grounded. Here are the pics of the compression tester and a few videos of the spark from the plug. Some in the dark and some with light.
http://i1271.photobucket.com/albums/jj635/Pabesco/08AE000C-86C1-4905-BF36-B20262481360-755-0000001C248D0E08_zpsff5990ee.jpg

http://i1271.photobucket.com/albums/jj635/Pabesco/75A25CC5-6EC3-4D9F-B538-C0F3E00881CA-755-0000001C0F0AE006_zpsf6d1c771.jpg

http://i1271.photobucket.com/albums/jj635/Pabesco/1C153AD5-45A8-46C4-A753-4C33A68B5E54-755-0000001BC1AC4D3D_zps770eb57f.mp4

http://i1271.photobucket.com/albums/jj635/Pabesco/B0060A12-75F4-4FAB-B2DA-2D04362328ED-755-0000001BA64E68BE_zpsfea3d3fc.mp4

http://i1271.photobucket.com/albums/jj635/Pabesco/0C9E63B0-238C-4BD0-8F10-51A5967990AF-755-0000001B1FAB2BCD_zpsd9a60760.mp4

http://i1271.photobucket.com/albums/jj635/Pabesco/CD0C8BD8-872D-422A-8E65-F4DC9EF18590-755-0000001AF4FD8F43_zps7b3b00be.mp4

Hope they are clear enough

[Pabesco]

http://i1271.photobucket.com/albums/jj635/Pabesco/CD0C8BD8-872D-422A-8E65-F4DC9EF18590-755-0000001AF4FD8F43_zps7b3b00be.mp4 (http://s1271.photobucket.com/albums/jj635/Pabesco/?action=view&current=CD0C8BD8-872D-422A-8E65-F4DC9EF18590-755-0000001AF4FD8F43_zps7b3b00be.mp4)

[Pabesco]

Sorry I'm trying to post the videos from my iPhone but with no success. I wl use a laptop to send.

[Pabesco]

someone please remind me how to post video using photobucket,

[Weldangrind]

someone please remind me how to post video using photobucket,

http://www.chinariders.net/modules.php?name=Forums&file=viewtopic&t=11188

[Weldangrind]

I fixed your video links for you. The third video is the only one that is easy to see, and you have a strong spark. As Spud says, hold the spark plug firmly against the head (or some other metal surface), so as to not damage the CDI.

[SpudRider]

The spark is excellent. You aren't having any problems with your electrical system. :)

Now you need to check the engine compression, and report your results. ;)

Spud :)

[katoranger]

I am curious to see the results of the compression test.

[FastDoc]

Some of the worst wasted time I have had as a 'mechanic' was related to not checking the compression earlier in my diagnostic workup.

My Zong 250GS, and my Honda XR250L come to mind. :cry:

[Wild_Alaskan]

that spark is great! sounds like your battery is weak or dying in the last video though. I found when my battery was low on my lifan it would only start with the kick starter because it would spin to slow.

also could someone explain how not grounding the plug damages the cdi? doesn't make any sense to me.

[FastDoc]

I don't know but I have heard that before also, including on Dan's website. I have also read about it in a shop manual or two, including my YZ400F's. It may be an OWT (Old Wive's Tale) but it is something I'm careful about. :wink:

[SpudRider]

I don't know either, but I don't want to take any chances. ;) It's very easy to ground the outer electrode with alligator clips; why take the risk? :)

http://i442.photobucket.com/albums/qq146/spudrider/Engine%20Compression/EngineCompressionSprocketWear002.jpg

Spud :)

[Pabesco]

I took the chance of not grounding it so you all can see if the spark was jumping far enough. I will be sure to ground it out when I do the compression test. My battery is really crappy and needs to be changed. I saw a few on eBay being sold by eBay that is listed for many bikes including the xt225 and it costs about $30. It has the right dime too s but just a little shorter but I can always put a wooden block under it. It seems that they are being sold by eBay

(1) YTZ7S AGM Factory Activated Battery
Maybe you guys can give me your opinion on this battery before I purchase it.
Also since I have no electrical problem and if it does turn out to be bad compression what is the main cause of this? I know then I would have to take the engines top section off but what would most likely need to be replaced? I have a new piston. Piston rings. New valves. Valve seals and a new cylinder (not the head) also I have a full gasket set.
Thanks again guys.

[Weldangrind]

Pabesco, I mean no offence when I say this; the leading cause of low compression in a new motor is tight valves. You indicated that you set the valves, but is there a chance that they're too tight? Like Doc, I've failed to check compression in the past, and it has turned out to be tight valves.

Beyond that, it would be rings or a valve failure, like a chunk missing from the valve. I really doubt that you have those issues, since you can't hold your thumb on the plug hole.

[Wild_Alaskan]

the finger test is usually only effective for catastrophic failures. bikes that wont start because of low compression can often pass the finger test.

[Pabesco]

Absolutely no of fence taken. I will recheck the Val da again in the morning to make sure they are set th spec. I'm glad to hear that the problem might not be the head. That's the only part I dont have yet. Thanks guys.

[SpudRider]

As far as batteries, I highly recommend the Motocross YTZ7S battery I installed in my Zong. It has been working flawlessly for tens of thousands of miles. :)

http://www.batterystuff.com/powersports-batteries/YTZ7S.html

http://www.batterystuff.com/images/products/418z_YTZ7S_Motocross_Yuasa_Motorcycle_AGM_Battery_ lg.jpg

As you can see printed on the case, this battery is manufactured in Japan. In fact, this battery is manufactured by Yuasu, and given the Motocross label. Therefore, if you purchase this particular battery, you are getting an excellent, Yuasu battery at a lower price. ;)

http://www.tristatebattery.com/what-is-motorcross-brand-by-yuasa-p-1016.html

Spud :)

[SpudRider]

Absolutely no of fence taken. I will recheck the Val da again in the morning to make sure they are set th spec. I'm glad to hear that the problem might not be the head. That's the only part I dont have yet. Thanks guys.
Please tell us the method you use to check the valve lash, and the values you are getting for both the intake, and exhaust valves. :)

Spud :)

[Pabesco]

Will do tomorrow and post results. I will order battery tomorrow also.
Thanks guys

[Pabesco]

I rechecked the valves and they are set as follows.
Intake 0.07
Exhaust 0.13
I recieved the compression tester adapter but it is too small (10mm) that is what an employee in the motorcycle store told me was the size I needed but it looks like I need the 12mm. Can anyone confirm this for me please.

[FastDoc]

Can you measure your spark plug? Or bring it to the hardware store where they have a gauge that you can thread bolts into and it tells you the size.

Sorry I don't know the size offhand...

[SpudRider]

Yes, you need the 12mm adapter. :)

Spud :)

[Pabesco]

I'll do that tomorrow

Thanks

[Pabesco]

Ok thanks spud. Just ordered it. I'll see if I can find something tomorrow to convert from 10 to 12 so I can test ASAP.

[Pabesco]

http://i1271.photobucket.com/albums/jj635/Pabesco/DE1DC7D2-BB97-4A73-B8E7-35869379B601-333-000000291140BEE6_zpsbfad610f.jpg

http://i1271.photobucket.com/albums/jj635/Pabesco/2B78EC9D-394D-4D3D-8366-F571CC094B3E-333-000000290204B68D_zpseab08513.jpg

http://i1271.photobucket.com/albums/jj635/Pabesco/80D036C9-06F7-4320-B573-7F6FB20DA8F6-333-0000002909AD98D7_zpse1a81313.jpg

http://i1271.photobucket.com/albums/jj635/Pabesco/82EFB8A6-9D38-48BC-8995-120B20765E8E-333-00000028F9EC0182_zps03c36565.jpg

Good evening guys. Hope all is well. I finally got the correct size adapter for the compression tester and performed the test. It was performed four times and the pics above are the results. Is this good compression or do I need to check the engine now?
Thanks guys and hope to get some feed back soon. I'm desperate to be back on the road.

[Pabesco]

I also purchased the recomended battery so I don't have a problem while testing again

[Wild_Alaskan]

looks good, this also means your valve timing is correct, this narrows down the potential problems alot.

I would say its either:

the ignition timing is off via sheared flywheel woodruff key

your gas is bad or there is water in the lower part and you have switched to reserve.

since it wont start or pop on starting fluid, i would bank on there being a problem with he ignition timing.

[SpudRider]

This thread is now eleven pages long, so I don't remember all the details. ;) Did Pabesco say he couldn't get the bike started with starting fluid? Did he say he can't push start the bike?

Having torn my Zong's engine apart several times, I am well familiar with its design and manufacturing quality. Based upon my experience, I would be extremely surprised to discover the bike had either a sheared woodruff key, or any timing problems. Therefore, I think the problem is fuel related. ;)

If you need the bike for transportation, and you can't fix the problem yourself, perhaps you should take the bike to a Yamaha mechanic. Your Zong's engine and Teikei carburetor are virtually identical to the engine and carburetor in the 2013 Yamaha TW200 motorcycle. Any competent Yamaha mechanic should be able to diagnose the problem. ;)

You've acquired a lot of tools, experience, and knowledge working on this problem. :) You will never lose the skills you have gained. However, if you can't fix the problem, perhaps it's time to let a professional mechanic take a look at your bike. ;)

Spud :)

[Weldangrind]

I agree that it sounds like a fuel problem. If you can drain the fuel and replace with fresh fuel, perhaps that will help.

[katoranger]

It should run with 115psi of compression. I think its alittle low, but you are reading on a cold engine too.

http://www.dansmc.com/compression_test.htm

With the spark we saw it has to be fuel related.

[FastDoc]

Was that taken with the choke and throttle open?

I don't know Zong specs but I would think normal to be around 150.

[SpudRider]

FastDoc is correct. If measured properly with the throttle wide open, a healthly Zong engine should have compression closer to 150 psi. Pabesco's compression readings indicate one of two things. Either he didn't hold open the throttle while testing the compression, or he has compression problems. ;)

Once again, I encourage you to read, and follow the techniques detailed in the following thread. :)

http://chinariders.net/modules.php?name=Forums&file=viewtopic&t=7807

Spud :)

[Pabesco]

all four times was with the throtle wide open and cranking for a total of 10 seconds each time.
i drained the gas and replaced with fresh gas also. i attempted to start it a few times and one time i heard some type of knock (only one time and loud enough to really hear), i decided to try rolling the engine again and didnt hear it again after trying to start it three more times,
if the throttle was wide open and tested with that compression then it means i will have to lift the head?
according to doc and spud this is showing bad compression? is this correct?

[Pabesco]

hi spud do you think i should start a new thread now that the problem has been narrowed down?

[FastDoc]

http://www.dansmc.com/compression_test.htm

Even if 150 is normal it should still run well enough on 125, and it should start on 115.

According to Dan 100 PSI is the minimum. It should be 125 to 150.

[SpudRider]

A compression reading of 117 psi at sea level for the Zong is not that great. I regularly get compression readings of 148-157 psi at 4,600 feet above sea level, with a cold engine.

The Yamaha TW200 Service Manual describes how to check the engine compression on pages 3-10 to 3-11. I suggest you read that part of the service manual, Pabesco. The service manual states the minimum compression is 114 psi, at sea level, with a warm engine. Therefore, if your compression gauge is accurate, you are barely above the minimum compression.

However, if the compression is above the minimum level, the bike should still start. You would notice reduced power while riding as the engine loses compression.

I'll ask again. ;) Have you noticed either of the valves getting tighter between valve lash inspections? Are either of the valves completely tight when you check the valve lash?

Spud :)

[Wild_Alaskan]

It should definitely run with that much compression. Also when you got the new carb are you sure the idle is set open enough? perhaps the adjustment screw is backed out.

[Pabesco]

The valves when checked were always fine and didn't need to be adjusted. They were not tight but within specs.

[Pabesco]

I checked the idle screw when installing the carb and it was ok. The mixture screw I didn't check and will do so in the morning. My main question now is due to the compression reading, wether the bike is starting now or not, would I need th remove and check the head and cylinder and piston?
Thanks guys for the suggestions and information.

[SpudRider]

The compression is slightly higher than the minimum value, but the bike has enough compression to start and run. I would not tear the engine apart. You need to discover why the bike won't start.

The electrical system check outs, and you have good spark. You have adequate compression. Therefore, the problem is either air, or fuel. Both of these components are regulated by the carburetor. I forget; did you install a new carburetor?

Once again, if you need the transportation, I suggest you consider taking the bike to a qualified Yamaha mechanic. The engine and Teikei carburetor in your Zong are virtually identical to the engine and carburetor in a 2013 Yamaha TW200. ;)

Spud :)

[SpudRider]

Here's one other thing you can try. Remove the spark plug. Put a few drops of oil through the spark plug hole into the cylinder. Install the spark plug, and connect the spark plug wire. Then try starting the bike.

Spud :)

[Pabesco]

good morning to all, yes it is a new carb. i asked a bit earlier if the carb comes new set to specs or if there is something that needs to be set, i checked the mixture screw and set it all the way in then backed it out two and a half turns.
i will start a new thread because this one is too long, i will post a summery of what was done and tested with all results, is it also possible for the bike to start if i remove the cover for the air filter?

[SpudRider]

good morning to all, yes it is a new carb. i asked a bit earlier if the carb comes new set to specs or if there is something that needs to be set, i checked the mixture screw and set it all the way in then backed it out two and a half turns.
i will start a new thread because this one is too long, i will post a summery of what was done and tested with all results, is it also possible for the bike to start if i remove the cover for the air filter?
Yes, setting the pilot mixture screw (PMS) at 2.5 turns out is okay. However, setting the PMS at 3.0 turns out might help you get the bike started more easily. You can always adjust the PMS leaner after you get the bike to start. ;) Set the idle speed screw the same as your old carburetor.

Removing the air box cover won't help, but it also won't hurt, as long as you keep the foam air filter in place. ;) I think it's a good idea for you to start a new thread with a summary of the work completed. :)

Spud :)