Zongshen ZS250GS Engine Problems

[nukeman99]

Hello fellow Zong riders! I just recently aquired an 06 ZS250GS bike. It only has 400 miles on it as we speak.
The seller stated that it needed a coil or something to get it running and a new battery. Well so far, ive installed a new fresh battery, removed the carb and tank, cleaning them thouroughly. It started up but hesitated and shut down. Started it up again with the choke and it finally sat an idled. If i gave it throttle, it would try and die, so i pulled the choke slightly and reved it a bit.
I let it idle for quite some time, of course with a fan in front the engine to keep it cool and then rode it around the block a few times,.. Didnt do too bad, came back and closed up my shop, put my helmet on and some warm clothes and rode it on the main road.
I went about 3 miles and the first time i slowed down to an intersection , it kinda '' hi-cupped" a little til i throttled it more after turning the curve. Got another mile down the road slowing down to another intersection and it did the same thing. Throttled it pulling through the gears to get back up to speed and went another 2 miles or so down the road and finally turned around in a CVS parking lot.
Upon turning around it was acting up again, but worse,.so i kept on the throttle trying not to let it die. Got down the road about 3 miles and was gonna 'bypass' a light and when i slowed down, it died on me.
Needless to say, i couldnt start it until about an hour later. And was still a little hard to start.
I jumped on it and got back to the house about 3 miles from where she quit at and when i pulled into the yard, she quit again.
I havent messed with it since the other day and tried starting it, and ''no go''. It does have a new plug set at .025''. Originally it was set at .029'' So before i went to start it back up i reset the plug today and it wont even hit a lick! Dont really know what to do at this point. I checked the fire at the plug before starting it and its very weak. Is that normal? I have push lawn mowers that have 10x the fire at the plug than this bike does.
Anyway,. just wanted to get some input on what im looking at or maybe something i may have overlooked. Im frustrated alot and being it let me down im having doubts already.
Thanks for your help fellows.

[FastDoc]

Welcome to the forum, and I feel your pain. On the bright side you are doing better than me, I've not been able to get mine to start at all. See my thread, I've been reassimilated for details.

My spark was also very weak. I replaced the CDI, coil, and stator and it is still weak. I compared it to another bike in the garage, and I'd say it looks about 1/2 strength, FWIW.

To me though your issue sounds more like the carb. It seems to me like old gas and water or some crud from the tank getting into the carb. How long did the bike sit before you got it?

I'd spray a shot of starting fluid into the air cleaner. If the bike starts and runs a moment the problem is not spark, but carb. If that's the case I'd reclean the carb and install a filter in line. Not a bad idea anyways.

Mine does not start even with starting fluid, not a single heartbeat.

I'm dissapointed in my Zong.

I wish you better luck.

Maybe between the two of us we can figure this out.

[Weldangrind]

Welcome nukeman99!

I encourage you to start a new thread about your bike, and you'll get more exposure and more help.

In the meantime, you say that it does have a new plug, does that mean you bought and installed a new plug, or the PO installed it? There have been several reports of fake NGK plugs, so I encourage you to buy and install a new one (they're cheap).

[SpudRider]

Welcome to these forums, Nukeman; we are glad you joined us! I agree with Weldangrind; if you have not done so already, I suggest you install a new, NGK spark plug. If the new spark plug doesn't work, I suspect you might have a bad CDI unit.

To help you get the most responses and the best help, I moved your post and started a new thread for you.

Spud

[nukeman99]

Thanks fellows for the welcome...
Well to answer a few questions,. i have thoroughly cleaned the carb and the tank exceptionally well. The PO has someonelese clean it but never had any luck. So anyway, the kit the bike comes with had an extra plug that i installed, that was never used. So i gapped it and put it in. For the most part, when it does decide to crank up and run, after 5 or 6 miles down the road, it quits running. And i have to wait til it cools off for the darn thing to crank! Fast Doc,. are you saying that yours had the same problem Weak fire? .... and then you replaced all three units? And that did not correct the problem? Oh man that sucks!! Where did the parts come from? Man i cant beleieve that, disappointing id say. I dont know what to do at this point. i set the carb at 1 1/4 turns out but i havent tried the starting fluid in it yet. I have though, used a small clear fuel line and put it directly into the combstion chamber. Still no go, plug comes out wet.
Well maybe i should just buy a new plug anyway.. .025'' on the setting ,.correct? Does anyone else have the same problem.? What would be a good test is to find someone with a RUNNING zong, same as ours and have them check the fire, to see if that is normal? What do ya think? Thanks fellows.. spud and weldangrind... look forward to your replies...

[Weldangrind]

Yes, for the low cost, I'd certainly buy a new plug. Which plug are you using?

[nukeman99]

Had to get away from it for awhile today and recharged the batt. so i decided to go back out and check the fire again. When i ground the plug to the cylinder, now im getting a broken or intermitt fire and still weak like Doc is having.
Ironic id say,. 2 bikes with the same weak fire? Or is it just coincedence? . Yeah, talking about frustration vacation, im pushing the same bike up the same hill obviously.!!!
The plug im using is a DR8EA NGK and i set it at .025'' is that right? Ill probably go out and purchase a new one tomorrow. thanks fellows...

[Reveeen]

I may be completely out of my mind here, but if this was my bike, and I was looking at the wiring diagram (see Docs post), the feed for the coil has a wire running off of it to run the tachometer. If this wire was able to be unplugged, I would unplug it, as close to the coil/CDI as possible, to eliminate it (the wire itself and the tachometer) as a cause of trouble.

At the very least I would unplug the CDI and coil, putting an ohmeter between the wire and ground, and get a feeling if something was going on there.

[FastDoc]

Your gap is fine. I think the book says .028 so no difference.

If you put gas into the cylinder and it does not run and you have a wet sparkplug that implies that the problem is the spark not the carb. Unless it was very flooded. That's why I like the starting fluid trick. I did the EXACT same thing as you with no results. It's funny we have the same issue at the same time. It's also odd your's runs at all. Not as much as you push, uphill though.

I have a little more troubleshooting to do on mine but I basically pissed so I've been doing other things. I'll try Reveen's suggestion soon.

Is your battery fully charged? I'm trying mine off a car battery with jumper cables, no battery in the bike so that's not the issue in my case.

Maybe my NEW CDI is also bad? Hard to imagine but possible, and no way to tell.

BTW Spud is a Zong parts dealer and your best asset if you need parts.

[Reveeen]

It's really strange that the both bikes would have a weak spark, especially the one that has had a new ignition system installed, makes me *think* a wire is chafed (under the tank?), or the tachometer is somehow to blame.

Oh! And Doc, if we could figure out a way to get the thing over the border, I would have hurt myself getting the $200 to you (per your other thread).

Hey guys, I was reading all the posts and everything and first of all happy new year jeje :P
i currently have a running gs250, it gives me some problems to start it. I just have to reroute the wires from the stator. No big deal.
Any way, I just bought this bike about 2 or 3 weeks ago, it has about 1700 miles on it and it runs perfectly. The guy that sold it to me did say that he replaced the CDI, the Coil and the Rectifier. So i'm guessing that if it had a problem with it that-s how he fix it.
Another thing is that my bike doesn't have any gauges, i took them off to make a streetfighter, i don't know if that also plays a role in the intencity of the spark plug or not.
Anyway I checked my spark on my bike and it's perfectly normal.
If you want me to check anything else on my bike let me know, hopefully it will help a little bit to isolate the problems on yours

good luck !
Cyril GHISLAIN

[nukeman99]

Hey CG...Happy new Year to ya and to all a good night!!! Wait a minute, thats Christmas...lol
Must be nice having a running GS250 huh? We do appreciate your help in figuring out these electrical problems. Dont really know what to say about Docs problem. Ive got the same thing going on, but havent replaced any of the electrics yet as far as a weak spark.
U mentioned (re-routing the stator wires? ) Could you go more into detail? Dumb question i know, but why did you do that? Were you having the same issues? Thanks man.

Well it's kinda hard to explain what's happening to my bike. About 3 days after i got it, aparentely the wires that run from the stator to the bottom of the engine were shorcuting and creating sparks. So I fixed it with a rubber hose that you put on and get hot and it shrinks and adopts the wire form. Then after that episode it started to act strange when I wanna start it. Sometimes I put the key in and lights will turn on no problem, turn signals horn and everything works, BUT as soon as you hit the start bottom, theres a click and everything shuts off. The i just move it around for a couple seconds, or break with the front brake or put up or down the kick stand and magicaly lights and everything come on again... Sometimes I have to do that for a couple minutes and finally it acts normally and crancks and runs right up. Sometimes i don't have to do at all.
But I remember that the first week after I fixed the problems with the wires it would start so I had to push start it. But it's been a while since last time I had to do that anyway.

The reason why I say I have to reroute them is also because I think they are waaaay to tight around the bottom of the engine and that's why they are melting because of the engine heat.

Hope you'll understand what I just wrote jajaja, english is my 3rd language :P

[nukeman99]

yeah i think i get what you are saying. I havent checked those wires yet and trace them out of the stator. Is that what u meant when you said the wires were too close to the bottom of the engine? Are they the stator wires and too close inside the casing behind the flywheel? Doc has replaced all his critical electrical components and still has the same prob as mine. So IMO, that makes me think He either got bad parts again, or theres another issue somewhere else..? Who knows..but thanks for your advice, i appreciate it and will check into it when i get the chance.

well I have no idea but today the most strangest thing ever happened. This bike has to have electrical issues somewhere.
I ordered some aftermarket blinkers that you stick on your fairings instead of the ugly factory ones. So I started to take them apart to disconect them and try the new ones on. Well I didn't touch anything but the connection between the blinker cables, and the principle ones. Somehow after I disconnected the old ones, I could not make the new ones work, impossible ! Tryed to put back on the old ones and they didn't work either .... I tryed everything but I don't have a voltmeter so I can't really figure out if I have electricity on the wires or not ...
Pain in the but !!! jajaja
As soon as I get a voltmeter, I hope I'll figure out something :P

All this just to come to the conclusion that maybe your problems are electrical :P It seems to me that something is not wright with this bike hehe