Hiyas folks. My son has a 2006 Kymco mongoose 90 which won't pull a hill. When we first got the quad my son could hold the front brake and gas it and spin the heck out of the wheels. Now it just bogs. I've cleaned the air cleaner & carb, installed new plug and belt. All the limiters have been removed from the day we brought it home. Any ideas on how much psi the cylinder should have? This quads a 4 stroke. When we check the plug its carboned up pretty good. We've tried setting the air screw. Still runs like crap. Any help would be greatly appreciated.

Thanks
Mike

 

I think your on ther right track (compression). It'll tell alot.

 

The exhaust might be plugged. Try removing the muffler (or maybe just the spark arrestor) A four stroke really should not carbon up the plug like that. My best guess would be the clogged muffler. It might have a bolt at the end of the muffler. If it does, remove that and pull out the spark arrestor first. If that does not help, remove the muffler from the pipe and try it. (obviously, it will be loud when you do that) Although it is possible, I doubt compression is the problem in such a new machine.

 

Our four stroke Eton 90 is supposed to have 120-140 psi compression. It is probably the same engine as they Kymco (or very close) I still think the muffler is the source of the problem though. [img]i/expressions/face-icon-small-smile.gif[/img]
Hope this helps

 

Ok folks to my surprise the problems not with the compression. The problems in the clutch. I just cant figure out what part. Variator or the clutch. I took out all the rollers and cleaned them then i took the variator halves and cleaned them then I cleaned the rear clutch bell and clutches and blew out all the dust with the air compresser and the quad was like new. Then while we down Hatfield McCoy trails my son tried to go up a really steep hill and it started acting up again.

When you pull the side cover off the rear clutch bell is blue. Is that from over heating or is that normal. Does that mean the clutches are worn or maybe the clutch springs or the main spring is worn? I really cant afford to take it to shop for them to test the springs and stuff. Any way someone can tell me how to do it? Or if they had this problem and its just the rollers or the clutches are worn out.

Thanks for any help. Its greatly appreciated.
Mike