So I've got a 92 Sportster. Just installed new exhaust and a breather kit about two weeks ago. Not until recently did I notice that after riding for about 15 min, or when the bike is warmed up my idle rpms shoot from 1000 to 1500, and stays although I'm stopped in neutral or first. Could an exhaust leak at the gaskets be the problem or something else?

 

Did you rejet?

 

Check:
1) Jetting.
2) Idle rpm setting.
3) Any intake/exhaust leaks.

 

Idle cable sticking a bit when warm?

John

 

lowspeed circuit is a little lean , have you adjusted idle mixture?
If not warm it up , then set your mixture on the rich side , re-adjust idle speed at the stop screw.

 

Looks like I found a fix to the problem. The carb looked like it slipped out the intake manifold just a bit (maybe moved it when putting on the breather kit). Just popped out the carb and fit it back in. All looks good now.

Appreciate the help!