Engine Trouble wont idle

[rj1967]

I have an 80cc that wont idle after it warms up. Dies every time I come to a stop. I think the problem is where the throttle screws on top of carb but not sure. Idle is all the way up and still stalls at stop. Also have a little slack in throttle. Can anyone tell me in me in laymen terms how to fix this? Thanks.

 

[Slogger]

Problems that crop up when the engine is hot generally mean it's too rich. My own bike didn't like to idle down and hold it until it was leaned out after break in time was finished. I'd pull up to a stop sign and *BUP* it quits. Then it would start right back up.
How's your engine running? Does it always run in 2 stroke or is it 4 stroking a lot?
You might also want to check your spark lead is making good contact at the plug and at the CDI.
Take the air cleaner off and operate the throttle, looking for the slide to rise and fall smoothly all the way.
Dirt in the carb (especially in the main jet or the float needle and seat) can cause it to run poorly also.
Hope you get it sorted out.
Regards!

 

[crassius]

yes, too rich is probably it - drop your needle down one slot & you'll probably be able to back out your idle screw quite a bit & still have good idle speed

 

[rj1967]

My needle is set on the notch closest to
the point..im assuming to get a little leaner I need to come up one notch..is that correct? Thanks guys

 

[Slogger]

Yep, and maybe two notches..
Raising the clip drops the needle, leaning it out.

 

[rj1967]

Ok ill try it. Thanks

 

[rj1967]

Ok..got good idle but loss of power. Anyway to compensate?

 

[crassius]

depends on whether motor has gotten around 300 miles on it yet - I rarely even try to tune them till then

if it is run in, then try one less notch on needle - if better, good, if worse, the float level can be adjusted to get about the same as a half-notch

all else fails, it's time to think about a new main jet

 

[rj1967]

Definitely run in. Float I think..need to push clip in a little or pull out a little?

 

[crassius]

turn carb upside down - standard is with main jet just peeking up thru float - leaner is jet just hidden by float - richer is jet sticking well up thru float