Carb adjuster

Yesterday the bike idled very high and I adjusted the knob under the carb. Today I can't get the idle screw to change the idle speed and I'm curious is it possible to strip the threads/ work it out too far?

Probably a dumb question but thanks in advance.

Bwildcat wrote: Yesterday the bike idled very high and I adjusted the knob under the carb. Today I can't get the idle screw to change the idle speed and I'm curious is it possible to strip the threads/ work it out too far?...

This might be caused by:
Needing throttle cable adjustment at the handlebar;
Something wrong inside the throttle fixture at the handlebar;
Internally frayed throttle cable;
Throttle cable binding or kinked;
Mechanical interference of some sort at the carb bell crank;
Carb return spring isn't doing its job;
Failure of the choke to close;
Air leak has developed somewhere;
Somebody messed with the pilot circuit adjustment screws.

IMO it's most likely not resulting from stripped threads related to the idle speed adjustment screw.

For a mechanical check, could manually assist full closure of the throttle mechanism at the carb.

Air leaks are typically from cracks in old deteriorated carb holders, or loose clamps holding the carbs inside the carb holders, or carbs not pushed fully into the carb holders. And there are also more possible air leak sources.

While idling at the high rpm, could spray WD40 or carb cleaner spray around suspected air leak areas (such as all around the carb holders) and watch for added smoke from the exhaust, which would indicate that the spray is being ingested into the fuel mixture from the carb.

Good Fortune!

I did replace the throttle cable a few months ago. I suppose it's possible that I didn't route it exactly the same direction. It did seem to make a difference how the bars were moved at one point so I'll check to see that the cable's cooperating.

Air leaks are definitely a possibility too.

Thanks for the speedy response!