47cc pocket bike walbro problem won't idle wlbro 668

[powerade510]

bike runs got but sometimes cutts out at wot . and has a hard time idling it will cut out. the carb is a walbro 668. but when i can get it to idel and not shut off wot runs great

[AZTIG]

got the same problem with my 49cc same CARB, hard to tune it!!! i broke to many spark plug just to find the right idle but sometime it just do the WOT! shet!!...smokey!!~~~

[Lhudgins1968]

problem with 668

read the post put up about my 668 walbro,it my help you too.

[npereira]

Most of theses issues are simple, yet most people dont think about it due to lack of experience.

The thing with carbs is you need to adjust the low speed FIRST!
once the engine runs good at idle, then you can move to adjusting the high speed needle. This is done by unscrewing the High speed needle 1 1/2 turn from closed (manufacturer suggested). The you keep making 1/8 to 1/16 turns (in) until it goes past the highest rpm and starts to bogh down (this indicates your in a lean condition) so start unscrewing the High Speed 1/16 turns until you get to the highest RPM peak. I them back out 1/16 turn from the highest point just to make it run a litle richer.

2 Stoke engines are very picky! You have just a small air leak around the carb, it is almost not ajustable.

Hope this helps.

1 thing I would suggest ADA is to include the Carburator Manual with the carb when selling since it has valuable information for tuning.