Leaderboard

Good information Ozark, hope that's it. Is this the part.

Hi. Yes you have a YFM450 and the specific model for parts or working in the service manual is the FAV.. You should be able to find a service manual in here that says it covers the FAV model.. The graunch into gear might be because the engine is idling too fast. That's pretty much the most common cause of it. It needs to be idling away at a nice slow pace. You should also check the clutch adjustment. There are two separate clutches in the quad, one is a centrifugal one and that locks up with revs to start the bike moving automatically. The other clutch is a plate clutch and it's operated by the same lever as shifts the gears. It's job is to stop gears crashing when we do gear changes at revs above the centrifugal clutch's lock up revs. The plate clutch needs adjusting from time to time.

The clutch adjustment according to service manual, loosen the lock nut, turn to the left until you feel resistance and then turn to the right 1/8 of a turn. Turning to the left loosens clutch and right tightens.

Ok so new flywheel is in and she fired right up. Huge difference, i can get to just about 80% throttle without any backfiring. The carburetor is still in need of tweaking but i think the problem is solved. Unreal that something like this can happen. What baffles me the most is the magnets on the old flywheel are solidly in place but yet they are incorrectly placed??? I tried to pry them off the flywheel with no luck. So strange! Going to get after the carburetor tomorrow and take it for a spin before i put it all back together. Keep ya posted.....