Chinese trouble

[mr pibbs]

I've got a scooter that is killing me.

Came to me with 4.5 miles on it. Died while running. I got it running for a bit, but now it wont stay running unless it is wide open and even then it is just barely getting by.

New gas
clean carb
stong spark
stady flow from tank
good compression

4 stroke

Any ideas?

[turtle13]

If it's got good compression, my first thought would be that its got an air leak somewhere.

[noiseguy]

Did you check the valve clearances?

[CaptainDudeMan]

Clean the carburetor change fuel lines & vacuum lines. The chinese fuel lines are crap they break down and gum up the jets in the carb. Check the vales gap they should be set at IN: 0.05mm EX: 0.05mm. I would also change the spark plug if its still the chinese one. If you need any more info for chinese scooters go to these sites
http://scootdawg.proboards.com/index.cgi
http://chinesescoots.forumwise.com/foru ... esescoots

[richdavison34]

I wish you the best of luck. The parts on those things are unbelievably cheap, and this issue might end up being more trouble than it's worth.

Sorry to be a Debbie-Downer, but I really despise anything Chinese.

[mr pibbs]

Still a problem... I think it is the CDI...

New vac/fuel lines
valve clearance set

new plug again
tested with another coil


I thought i had it sussed - ran up and down the road well, but then the symptoms appeared again - i think the plug is getting fouled with carbon.

Spark is there but seems more white than blue.

Weak spark not burning everything? What do you think?

[wiguy05]

I would suspect an air leak. I had a China scoot that I tried to get going before I ended up parting it out.....check the intake elbow for any dryness/cracks.

EDIT: Also check that the vacuum diaphragm thing on top of the carb is seated and sealing correctly! This thing drove me crazy until I decided to junk it out

PART #14 IN THE DIAGRAM

[mr pibbs]

But why would an air leak cause a jet black carbon fouled spark plug?

[CaptainDudeMan]

It sounds like your running rich. Is your spark plug gap set at 0.028"? black indicates a too rich fuel mixture and very light beige to white usually indicates a too lean of fuel mixture. Have you messed with the air/fuel mixture on your carburetor?

[noiseguy]

+1. Carbon fouling sounds more like rich than lean.

Have you pulled apart the carb to check? Could be something silly, like a loose main jet or jammed CV slide.

[mr pibbs]

Needle seat...

[noiseguy]

That will do it. A lot of reports I read on issues with Chinese motors are silly things missed in assembly... that or inferior fasteners.