CB900F Help Please

[Junk Collector]

I have a 1981 CB900F that has been sitting for sometime and won't run at low revs. Carbs have been cleaned and jets look OK. Will start and run OK at high revs but will not run unless revs are kept high. Any suggestions would be appreciated.

[riffer]

Does it run at low revs when warm?

Bikes like to run a bit rich when they are cold but will happily accept a leaner mixture once wamed.

Did you mess with the idle mixture screws when you cleaned out the carbs?

Have you checked the obvious?

1. Idle mixture/carb balance
2. float levels
3. air filter
4. sparks plugs

or even some weirder ones like rust buildup inside the exhausts from sitting a while can cause a bit of grief too.

[Bonez]

I have a 1981 CB900F that has been sitting for sometime and won't run at low revs. Carbs have been cleaned and jets look OK. Will start and run OK at high revs but will not run unless revs are kept high. Any suggestions would be appreciated.

Are you sure all the slow speed curcuit passages have been cleaned properly? Definately sounds like they're gunked up.