I recently change my FPR about a month ago. I suddenly notice the difference in the way the bike ran. Real smooth throughout the RPM powerband and 150+ miles per fill up. Then just recently the bike started to feel just like it did before I changed th FPR. Rough(vibrates a bit) throughout the RPM's and 120-130 miles per fill up. I also cleaned out the K&N as well. The only thing I have yet to do is spark plugs. My questions are:

Does this sound like a symptom of a defective FPR?

Has anyone had their FPR prematurely fail??

Is there something else I am not looking at??

 

FPR's are such a common problem I would say most are premature failures. However lots of things can cause said problem. I would replace the plugs first. While your doing that, go ahead and pull the vac line from the fpr and see if its leaking.

 

Adjust the throttle bodies, too. They could be way out of sync.