i turn my bike on this morning and immediately notice the rough idle. after it warms up the rpm's drop to 1k. i give it a little throttle and the rpms go back to 1300 but its still rough. riding in all gears is smooth, no surge or bucking. its only at idle. im guessing its the FPR. sorry for not diagnosing th FPR first, i jus wont have time till the weekend. for those of you that have had issues with the FPR, is a rough idle one of them? th exhaust is also rich at idle.

 

A bad FPR will start to cause the plugs to foul. Pull the vacuum line off the FPR & see if there is fuel in the line. If there is, its bad.

 

i plan on checkin it this weekend. i was gonna order a new one cuz im positive the FPR is the culprit

 

yup its a bad FPR. a new one i jus ordered should fix that up

 

Seems like the FPR goes quite often on these bikes ? Is taking off the vacuum hose and checking for fuel in it, the universal way of telling it's bad, besides the bike not running right ?

 

Pretty much an its th easiest one to diagnose for a problem when ur having riding issues.

 

yup. it's a mechanical part that, when it goes bad, ruptures the diaphragm inside and puts fuel back into the intake via the vacuum line. it can only fail by leaking inside or outside. if its leaking on the outside, it's obvious.

 

My bike is a 2001 929 with 2,756 miles on it, sat much longer than it was ridden obviously. Mine seems fine as far as the other symptoms of a bad one, but i'm going to check it anyway, and if it's good and I get ready to put a full summer on it, then it will probably fail. There is a new part number and it's a Keihin part, not sure what the original one is. But when you guys replace yours with the new part #, are you having any problems with that new one ? does it seem to last longer than the original ?

 

why do you think it will fail? my Erion had 80,000 miles on it, and it never failed. my current on has 15,000 and it hasn't failed, yet. replace it if you want to, but i wouldn't until it fails or if i'm headed cross country on it. keihin is the OE manufacturer.

 

I think it will fail because my fuel pump partially seized already and because the bike is 10 years old and just sat there unused most of it's life and sitting it what causes things like rubber to dry out and crack.I'm already worried about the longevity of my fuel pump, went out to start it after this winter just passed and the first 3 or 4 times I turned the key the fuel pump wouldn't come on and prime, finally turned the key 1 more time and then heard the fuel pump come on and prime, but it made a weird noise after it finished priming and shut off. It must have been seized and broke itself loose from me flipping the key on and off. So something wasn't right in there. I hate to leave anything like that sitting for such long periods of time, being that most fuel is up to 10% water ( ethanol ) these days.