high idle when warm

[kidnafarious]

i have a problem and maybe someone here can help

1981 cb750 when it warms up, it idles at about 3k
i checked the carb boots with carb cleaner to see if they are leaking

the carb boots dont seem to be leaking  because the idle doesnt change

can there be another vacuum leak somewhere???

its driving me crazy to roll to a stop at 3k rpm

could it be the air cut off valve???

im having trouble because i never worked on a carbureted engine

please help me

[bear69]

First, check the the throttle is not set too high. There is an adjuster knob on the underside between carbs 2 and 3. turn this clockwise (I think) to reduce the revs. (anticlockwise if the revs rise).

if this has no effect in reducing the revs, make sure that the choke is fully off. Sounds simple but mine was on the littlest fraction last week and held the revs up. Make sure the mechanism is fully off, it could be frayed cable.

Do these basics first and see where we go.

Have you changed the balance?

[cbRider]

Has the high idle problem come on by it self or did it happen after some work was done on the bike?

Karl