Did you change the pilot jet? If you go too big on the pilot, it will randomly surge and hang at idle.

 

Ohhh.maybe thats it ! I'll talk to my mechanic. Thanks.

 

Yeah, mine ran great except for I couldn't get the idle right. It would idle fine then jump up to 2000 rpm for 20 seconds than back to normal idle. Or it would hang when I came to a light. It just sporadically ran like this.

I tore my hair out trying to find vacuum leaks, clogged jets, etc. I finally put the stock 35 pilot in it and it fixed everything.

 

Was this with the 351 kit?

 

Yes, when I put in the big bore, I bumped up to a 38 pilot.

Could not for the life of me get it to idle right.

I don't know if its the elevation or what, but my bike apparently doesn't need a whole lot of fuel.

 

I see no reason that increasing the bore size would require a larger pilot jet, which controls idle mixture. Increasing the bore, does not result in much change in fuel/air requirements of idle speed.

 

Thanks.