I have a 2009 Ultra Classic that has a problem with rough idle and degraded performance when the motor gets very hot (for example, when riding home from work in stop-and-go traffic). I did a stage 1 upgrade to it a couple of years ago and the problem seems to have started after that. The upgrade included a Power Vision and associated tune file from Fuel Moto. I tried a few basic tune runs, but nothing really improved. About a month ago, I upgraded to Andrews 48H cams and got a new tune file from Fuel Moto. The hot rough idle/performance issue got worse, so I took the bike to a local tuner, had him put it on his dyno, and got a custom tune built for it. The performance of the bike when it's cold or warm is now fantastic (for a stock 96" motor with cams), but the hotter the motor gets the worse it performs and the idle gets to the point where it almost seems like it's going to stall. I don't mind taking the bike back to the tuner and asking him to fix the tune, but I want to make sure that's the problem. What other things could be going on to cause this issue on a hot motor - bad or failing sensors (engine temp, O2, etc.), exhaust or intake leak that gets worse (or better) when hot, fuel flow problem (vapor lock, failing fuel pump)? Any ideas/suggestions would be greatly appreciated.

 

Are you sure it's not the EITMS kicking in while you're idling in traffic? A EFI motor can't vapor lock but you could have a pinhole in the fuel line on the fuel pump.