Zongshen 250GS weak or no spark...

bgramster · 10-31-2011, 12:27 PM

ok, here's where i am:

1. Replaced Starter Solenoid
2. Replaced Battery
3. Replaced Kill Switch
4. Replaced Spark Plug and Wire to ignition coil

I haven't replaced the CDI and I haven't replaced the ignition coil. The engine is turning over just fine it just won't fire. The spark plug shocks me but isn't showing any spark when I touch it to metal.

In your all's opinion which would be the better guess CDI or Ignition Coil? (finding both are proving to be problematic, even the american companies aren't calling/emailing back)

Replacing the kill switch I noticed that there are 3 posts on both the old and the new switch, the way I have it wired at the moment the light in the switch (yes I replaced it with a switch with a light) only illuminates when I'm pressing the starter. The old switch didn't have any indication of what was neutral, + or - the new one just has a "N" on one of the posts, should this matter as long as one is on the "N"?

thank you all in advance for any help you might be able to offer,...also I am fantasizing launching this bike through the front window of the place I bought it from any good ideas on how to accomplish this without a catapult? jk, thanks

B

FastDoc · 10-31-2011, 01:10 PM

These bikes are well know to have problematic ignition systems

.

On mine I had to replace the stator, and stator cover gasket, and the CDI. I replaced the coil with a spare for another CB I had laying around and it made no difference.

Coils rarely fail, CDI failures are common. Stators less so but it happens :roll: .

BTW I don't recommend using a human subject to test for spark. 8O

bgramster · 10-31-2011, 06:42 PM

true, human test subjects aren't the best especially when they're me !...I'm thinking CDI as well even though this particular one doesn't have any miles on it, perhaps I've looked at it wrong. Anyone have any ideas on the other issues? thank you all

FastDoc · 10-31-2011, 06:57 PM

If you can get one the CDI is the right place to start. EVEN if it turns out to be something else you'll need a spare, and it's good for testing. Chinabike CDI's almost always fail, and commonly on nearly new bikes...

The good news is they are inexpensive.

bgramster · 10-31-2011, 07:07 PM

inexpensive, true, hard to get , true as well... I've called Zongshen 3 times today and 5 times last week, never an answer, never a call back, email doesn't seem to work either, any other places to get a CDI? not trying to use this as a private message board but seems like this is info anyone can use.

FastDoc · 10-31-2011, 07:14 PM

Spud used to be a Zong parts dealer but stopped I think because of problems like this...

It sucks because Zong's are good bikes for the most part but the whole Chinabike debacle is centered around poor parts availability. Unfortunatly I don't think that you can substitute a Yamaha or Hondoid CDI, the Zong part is a bit specific.

If a person knew what he was doing a suppose a different CDI could be wired to work but I have no idea how to go about that.

My ZS GS250 was one of the only bikes I've owned and given up on fixing and sold in non-running condition. It and that POS Pitster Pro I owned are the only bikes I've taken a loss on.

Consider PM'ing SpudRider, he will be the best source of information.

Keep us in the loop

.

Bill

bgramster · 11-18-2011, 01:16 PM

...update ...

3 and a half weeks later I have received my parts....

After installing a new CDI, new ignition coil and new right handlebar kill switch and enclosure I blissfully attached and then plugged in my new float charger to the battery, a few hours later took a deep breath hit the starter and......tadahhhh NOTHING !!!

Guys...what's left? The engine is turning but not firing, someone said to pour gas in the cylinder....where is the cylinder? I cannot figure out what is left that could be wrong, the stator was fixed when I had the engine rebuilt 2 years ago, all I can say is that the bike has not officially "run" in 2 years, any ideas?

FastDoc · 11-18-2011, 03:02 PM

I'm so sorry to hear about your lack of success so far.

As I may have mentioned this model bike is one of the few I've owned that I was not able to get running and sold it as a non-runner.

With my bike the problem turned out to be poor compression.

Remove the spark plug and place your thumb over the hole. Open the throttle fully and have the choke off. Pust as hard as you can with your thumb and hit the starter.

If the engine's compression is not enough to smartly blow your finger off the hole it is less than 100 lbs and will not run.

Another test is to put about 5cc of raw gas in the spark plug hole and replace the plug. If the problem is carburation only it will start and run about 10 seconds.

bgramster · 11-18-2011, 05:04 PM

sweet,... thank you for the feedback, I'll try this in the morning and post results. thanks again

davidstpek · 05-28-2020, 10:24 AM

Quote:

Originally Posted by bgramster

true, human test subjects aren't the best especially when they're me !...I'm thinking CDI as well even though this particular one doesn't have any miles on it, perhaps I've looked at it wrong. Anyone have any ideas on the other issues? thank you all

Did Bike have a 4 wire key switch? did you replace it? switch was made to connect white with brown when key is in run position the other two wires are for kill circuit. So operation is like this
Key off - white and brown open other 2 wires closed (kill circuit-enabled)
Key on - white and brown closed (12vdc to bike) other two wires open (kill circuit disabled)

Even with kill circuit enabled holding (Human) onto sparkwire end will zap you... but not enough spark to arc plug to ground.
NOTE: Normal voltage to spark plug is close to 40,000 VDC... Thus is able to stop heart... SO BE DAMN!!! CAREFUL!

I would try this first.
1. unplug key switch
2. in Bike harness with jumper... Jump white from battery (could be red) and brown in harness. Now going anywhere on bike harness to ground with meter there should be expected 12VDC, in not check fuse in harness at Battery lead to bike 12VDC+ should be wite wire. there coud be a lead feeding red wire from rectifier also off this lead, can't remember if it was before or after fuse. I believe it was before fuse to enable charging of Battery.
3. Leave the other 2 wires alone. I just looked at my Bike these 2 wires are Black w/yellow stripe and black w/white stripe. if at this point you could go to rectifier and pull pin wire (Black w/white stripe from pin harness plug. care and you can reinstall when done. Doing this will totally disable kill circuit! So insure you are in neutral.
4 if still in dark won't start does your bike have a clutch switch? if you trace back to main harness you will find a diode connected between here and neutral pin at gear selector and negative post on stat relay. If this diode it is a plugin 2 pins look like T or L configuration. Get one and switch out. if it is bad (they will burn) engine will not start!

This is all I can think of for now. Oh before I forget if after removing Black w/whit stripe wire from harness bike starts I would run new wire from key switch Replace or jump out Black w/yellow stripe... It is shorted between rectifier and key switch!

Good Luck!
David

I have a gut feeling that ignition is semi grounded disabling full spark for engine to fire.

franque · 05-28-2020, 10:30 AM

This is a 9 year old post.

10-31-2011, 12:27 PM	#1
bgramster Join Date: Sep 2011 Posts: 15	Zongshen 250GS weak or no spark... ok, here's where i am: 1. Replaced Starter Solenoid 2. Replaced Battery 3. Replaced Kill Switch 4. Replaced Spark Plug and Wire to ignition coil I haven't replaced the CDI and I haven't replaced the ignition coil. The engine is turning over just fine it just won't fire. The spark plug shocks me but isn't showing any spark when I touch it to metal. In your all's opinion which would be the better guess CDI or Ignition Coil? (finding both are proving to be problematic, even the american companies aren't calling/emailing back) Replacing the kill switch I noticed that there are 3 posts on both the old and the new switch, the way I have it wired at the moment the light in the switch (yes I replaced it with a switch with a light) only illuminates when I'm pressing the starter. The old switch didn't have any indication of what was neutral, + or - the new one just has a "N" on one of the posts, should this matter as long as one is on the "N"? thank you all in advance for any help you might be able to offer,...also I am fantasizing launching this bike through the front window of the place I bought it from any good ideas on how to accomplish this without a catapult? jk, thanks B
	0

10-31-2011, 01:10 PM	#2
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	These bikes are well know to have problematic ignition systems . On mine I had to replace the stator, and stator cover gasket, and the CDI. I replaced the coil with a spare for another CB I had laying around and it made no difference. Coils rarely fail, CDI failures are common. Stators less so but it happens :roll: . BTW I don't recommend using a human subject to test for spark. 8O __________________ Happy to serve.
	0

10-31-2011, 06:57 PM	#4
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	If you can get one the CDI is the right place to start. EVEN if it turns out to be something else you'll need a spare, and it's good for testing. Chinabike CDI's almost always fail, and commonly on nearly new bikes... The good news is they are inexpensive. __________________ Happy to serve.
	0

10-31-2011, 07:14 PM	#6
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	Spud used to be a Zong parts dealer but stopped I think because of problems like this... It sucks because Zong's are good bikes for the most part but the whole Chinabike debacle is centered around poor parts availability. Unfortunatly I don't think that you can substitute a Yamaha or Hondoid CDI, the Zong part is a bit specific. If a person knew what he was doing a suppose a different CDI could be wired to work but I have no idea how to go about that. My ZS GS250 was one of the only bikes I've owned and given up on fixing and sold in non-running condition. It and that POS Pitster Pro I owned are the only bikes I've taken a loss on. Consider PM'ing SpudRider, he will be the best source of information. Keep us in the loop . Bill __________________ Happy to serve.
	0

11-18-2011, 03:02 PM	#8
FastDoc Join Date: Mar 2009 Location: Southeastern Washington desert Posts: 14,761	I'm so sorry to hear about your lack of success so far. As I may have mentioned this model bike is one of the few I've owned that I was not able to get running and sold it as a non-runner. With my bike the problem turned out to be poor compression. Remove the spark plug and place your thumb over the hole. Open the throttle fully and have the choke off. Pust as hard as you can with your thumb and hit the starter. If the engine's compression is not enough to smartly blow your finger off the hole it is less than 100 lbs and will not run. Another test is to put about 5cc of raw gas in the spark plug hole and replace the plug. If the problem is carburation only it will start and run about 10 seconds. __________________ Happy to serve.
	0

10-31-2011, 06:42 PM	#3
bgramster Join Date: Sep 2011 Posts: 15	true, human test subjects aren't the best especially when they're me !...I'm thinking CDI as well even though this particular one doesn't have any miles on it, perhaps I've looked at it wrong. Anyone have any ideas on the other issues? thank you all
	0

10-31-2011, 07:07 PM	#5
bgramster Join Date: Sep 2011 Posts: 15	inexpensive, true, hard to get , true as well... I've called Zongshen 3 times today and 5 times last week, never an answer, never a call back, email doesn't seem to work either, any other places to get a CDI? not trying to use this as a private message board but seems like this is info anyone can use.
	0

11-18-2011, 01:16 PM	#7
bgramster Join Date: Sep 2011 Posts: 15	...update ... 3 and a half weeks later I have received my parts.... After installing a new CDI, new ignition coil and new right handlebar kill switch and enclosure I blissfully attached and then plugged in my new float charger to the battery, a few hours later took a deep breath hit the starter and......tadahhhh NOTHING !!! Guys...what's left? The engine is turning but not firing, someone said to pour gas in the cylinder....where is the cylinder? I cannot figure out what is left that could be wrong, the stator was fixed when I had the engine rebuilt 2 years ago, all I can say is that the bike has not officially "run" in 2 years, any ideas?
	0

11-18-2011, 05:04 PM	#9
bgramster Join Date: Sep 2011 Posts: 15	sweet,... thank you for the feedback, I'll try this in the morning and post results. thanks again
	0

05-28-2020, 10:30 AM	#11
franque Join Date: Nov 2017 Location: Marseille, France -> Conakry, Guinea Posts: 1,481	This is a 9 year old post.
	1