View Full Version : 50cc carb issues

06-30-2008, 08:45 AM
Hi everyone - I just picked up a little 50cc for my kids to ride in the yard. Its in great shape almost brand new - bought it used.

The bike starts well w/ choke when cold and w/out choke when warm. When up to normal operating temp it idles very high (choke is off) almost to the point that it takes off - after idling for a little while the idle will drop down to a more normal idle range, then slowly increase back up to that high idle where the bike almost starts to move.

I dont have any rpm meter but the change is drastic. I ruled out a cable issue b/c the bike is just sitting there - the cable is not moving or being pulled on and the rpms go up and down.

I pulled the carb and cleaned it out completely, removed the jets and blew everything out etc. Right now the air/fuel mix screw is about 1/8 to 1/4 turn out (which doesnt seem right) - what could be the issue - or do i need a new carb? Help please!! Thanks!

02-19-2009, 08:35 PM
I see this is an older post but for prosperity ~~~ last time I ran across this issue it was due to stale gas. The gas would run the bike Ok, but it looked funny when I drained the carb onto the drive way. The fuel just didn't spread out right.

Fresh gas allowed me to readjust the carb to improved settings that worked consistantly.

06-12-2009, 09:18 AM
I just looked at my oringinal post on this and I've been chasing this problem for a YEAR! Last night I finally solved it!

I bolted on a new carb and basically had worse results than the original carb. Something is screwy...I happened to read the carb tuning tips on G-forcepowersports web site and "air leak" kept jumping out at me (i've read it all b4 too!) Anyhow, last night i took a real good look at where the carb bolts to the metal intake tube and you could visually see a tiny gap! son of a...... Mixed up a little 5min epoxy (cause I never want to take it apart again) and walla!!! Fired right up and could actually tune it and have it idle really nice and low like a good Honda Clone should. Knock on wood this might be the best running bike I own ....lol...

hope this helps someone else

happy wrenching