My bike has decided to start refusing to come back down to idle like it should. If the bike is off, I can twist the throttle and release it, and it snaps right back closed. However, if i do it when it's running it hangs stubbornly and will eventually work its way back down. Sometimes at a stop light it wont want to come any lower than 3k, the next stop light could be 1250rpms though.

Any ideas? Throttle cables needing lube, could it be jetted too lean?

If it only does it while running, it's not the cables needing lube.

Sounds like an air leak around the intake to me. Or maybe a hole in the diaphram? That's just a guess though.

Very Plausible.

Could being too lean cause this sort of problem? Its a red flag just because the mechanic that looked the bike over thought the 150s were way too big for my intake, full exhaust and stock needles, so he put in 135s. Everyone here seems to run 147.5-150 though.

I run iirc 142.5 main and 40 pilot. RAN perfect. (mods in sig) did the carbs have the same issue with the 150 mains?

sounds like you need to adjust your idle; ride your bike hard for 15+ min or til it the idle starts to hang like that, then lower the idle so that the rpms always go back to normal.  Your valves may be getting out of spec, may be time for a valve clearance check.

Valve clearances are in spec, and I've played with the idle screw, it will fix it one time, but then the next time it will try to idle at 750. I think I'm going to try backing out the fuel screws like it says in the FAQ section.

could be time for a carb sinc

If you figure it out, let ver4 know what you did   

-Jessie

Quote from: BaltimoreGS on August 29, 2010, 05:59:06 PM
If you figure it out, let ver4 know what you did   

-Jessie

Fo' shizzle.  It's been three months and I still haven't figured it out.