hello I have a 2006 f4i with 37k miles on it and recently it has developed a vibration with motor rpm. I can feel it through the whole bike handle bars, foot pegs, frame, gas tank, i notice it mostly at 5000-9000rpm but it seems to diminish after 9000 rpm but stilll their just not as bad. it will happen reving the bike in neutral parked. so i know its not chain and sprocket or tire related. i replaced spark plugs. checked every bolt on the bike for looseness. readjusted ape tentioner. put factory exhaust back on. took off power commander. motor makes plenty of power and idles smooth. so now im kinda at a loss. my only thought is can valves too tight cause a vibration? any other ideas i should check? ive taken the bike too 2 different motorcycle mechanics to ride the bike and they both said it was weird and they had no idea. so any help would be greatly appreciated.

 

I don't think valves would do that, if valves are too tight they'll cause hard starting issues when the bike is cold (and get better when warm) generally.

It's hard to say what it is, I haven't heard of that specifically. Sounds like something is out of balance though, and resonating at those rpm's 5k-9k. I've seen clutch'es break (but still work fine) and throw the engine out of balance. I'm not sure what else could cause it. The clutch idea is just a guess though.

Have you drained the oil? If not, I'd change it, and when do drain it, have 2 clean clear cups/jars or what I like to use, water bottles with the top cut off.... Soon as you open the drain plug, catch the first little bit of oil to come out (just like 1-2 inches in hte water bottle), then as the oil is slowiny down almost done draining, catch the end of whats coming out in another bottle

and look at it through a right flashlight. Gold flakes are baaaaad, silver not so bad

 

Yeah I agree something may be out of balance and I did change the oil when I did the spark plugs. The clutch is pretty new I did it towards the end of last riding season and when I changed the oil it had some small metal in it and i figered it was normal due to the new clutch breaking in. Can throttle bodies out of sync cause vibration? Do crankshafts ever bend on these motors? What about timing chain stretching? Or maybe the stator out of balance? I'm just running out of things to check. I'm going to take it to a third motorcycle mechanic next weekend. If I can't figure it out.

 

Ok update everyone. I took the bike to a third shop and they specialize in race bikes. They looked it over and said that it was running a touch lean and I needed my injectors cleaned and that this is real common on race bikes but not much on street bikes and saos I must be beating the **** out of it to do that. Well I do ride as hard as possible so I took the bike and put some injection cleaner in my fuel and what a difference it made the bike is already almost back to normal.

 

Thanks for the update! I'm new to the F4i and trying to learn as much as possible so "hanging" threads frustrate the hell out of me!