OK, first time posting but often visitor for research.
Problem; Engine light comes on a 2004 FLSYFI (See below) with high RPM’s only. If I shift early and do not much more than 50 light stays off.
Attempts; 1] This began when I added the front spoiler thus remounting the voltage regulator, therefore I originally thought it was a grounding problem but numerous regrounding configurations failed to eliminate the problem.
2] My favorite shop found no fault codes new or old.
3] Researched and suspected the CKP sensor. Changed it to no avail.
Question; WTF is it? Could it be the computer? A gremlin?

Any suggestions would be greatly apprecitated.

PS the bike runs fine with the light on or not!

 

This could be so totally off base that its ludicrous but is there any chance your oil is a bit low. I had a metric bike years ago that did that if the oil was just a bit low. At higher RPM it was pumping oil up faster than the oil could drain back down and therefore the sump was reading low even though there was lots of oil. But if you overfill you end up blowing it out somewhere so finding the right level is a bit of a balancing act. Probably not your problem but something to look into if nothing else turns up.

 

AHHHHHHHHHHHHHHHHHH!!!

Sorry about the typo. Not a FLS-Y-FI! FLSTFI!! Makes me look like a dweeb. Sorry, and thanks dbinbc, I'll give it a check out!

 

it is a check engine light ,could be any number of things. like dbinbc said check all fluids, air cleaner etc . you would think a code of some sort would show.

 

Nope, dbinbc not the oil level. Checked fluids and the air cleaner is brand new. No codes either. And If i rev just once then no matter how slow i glide afterward the light will stay on. Thanks jaqmes for the reply, though. Any other ideas? I could use a little dab of tape and make it go away.