My 2005 Heritage is having an issue. It's fuel injected. When cold it will run perfectly but as it warms up it begins to misfire. The hotter it gets, the worse it gets. If I roll on full throttle though it will clear itself and pull hard, but at normal cruising speeds it is so bad that its unrideable. When I allowed it to idle, I noticed the pipes were cherry red by the heads. Pulled the plugs and they were both white. What is causing this extremely lean issue? CKP sensor was replaced so that is not the issue. I read about others having similar issues but nobody came through with an answer. It has NGK plugs with stock wires. Thanks in advance.

 

Check that the IAC isn't stuck open. IAC is Intake Air Control valve. Its job is to replace the choke on carb models. It allows extra air into the engine when cold... when the ECM is commanding extra fuel, too. If stuck, and the ECM stops commanding that extra fuel, it can make a bike run extra lean.

When looking in the throttle body, it is a hole right inside at the top. Spray carb/EFI cleaner at it. If that don't work, remove and clean usually does.

 

My guess is your intake seals are leaking. Start the bike up and let it idle, then spray a generous amount of carb cleaner whre the intake goes into the heads, from the Air cleaner side. If the bike changes idle you found your problem.

 

Thanks for the leads. I will check that out this afternoon and post the results.