LANCER wrote on 08/19/09 at 17:44:03:I pulled into the street and attempted to cruise down to the corner at about 1/8 throttle. The engine did not like that. It surged horrible. too rich symptom
Color me confused.
Let me repeat the steps I took, perhaps there was a miss communication.
- Start motorcycle with "choke" on first notch
- Let idle for 30-60 seconds, notice it's not a smooth idle, rev and push choke in - idles smoothly
- Let idle for 30-60 seconds
- Attempt to leave, as soon as I open the throttle the engine behaves badly. I don't know the technical term. I'd describe it as a surging or hunting. RPM varied wildly.
- Pull choke out one notch.
- Runs better (not perfect) at 1/8 throttle, idle still rough
- Once warm, push choke back in, runs "fine" at all throttle openings
Caveat: cold engine is not a valid test configuration
What this tells me is the engine is getting a richer mixture at 0 throttle than at 1/8 throttle. Perhaps it's too rich at idle, perhaps it's too lean at 1/8 throttle - that'll require a warm engine to identify.
Since that whole range is primarily controlled by the pilot jet and mixture screw, I'm not sure how to fix that. Or if it's something that needs fixing.
-D. Dwarf