quick question. i have an 01 F4i with 25k miles. recently (within the past 2 months) i have noticed that when holding the throtle at a constant, the rpms seem to jump around. it gives the bike a jerking motion and is very uncomfortable when you ride it. example: lets say i am going at about 40 mph in 3rd gear at about 5k rpms, well the tac seems to jump between 5000rpms and 5500rpms. it does this in every gear. i thought it was the plugs, so i changed those to the NGK plugs. thought it was the air cleaner, so i bought a K&N. but the bike still does it. i have been having problems with the battery, but i dont think low voltage would make it run like that. am i wrong? any input is appriciated.

 

Could possibly be a TP sensor or something along those lines. Is the FI light on? Have you taken the bike apart at all, maybe something (map sensor vacuum hose or electrical connector, IAT sensor, etc) could have been left unplugged?

 

the FI light is not on. i took the bike apart a few times looking for unconnected vaccum lines and when i put the new plugs in. everything seemed fine. i have not had the valves synced in about 12k miles. could that be the problem?

 

Nah I doubt the valves would have anything to do with it, and 12k isn't much at all on them (hell I went 41k before my first valve adjust (yea...oops!), and none were out of spec). My bet is on the TP sensor. You don't have a power commander, right? I'm about to head out the door now but when I get back I'll look up how to check it

 

yea i dont have a power commander. let me know how to check that TP sensor and i will have a project for tomorrow. Thanks Jared

 

Page 5-82 of the service manual goes into great detail about checking the Throttle Position Sensor voltages.

 

I would unplug the P C and see if your problem goes away...I have seen them do funny **** to peoples bikes

 

i had a simmilar problem like that but forgot the rpm range and it turned out to be a lose battery termanal

 

I had similar symptoms when i first got my F4i, but it had really low miles. It is an '01 and only had 3200 miles on it when I got it, and it had not been ridden regularly for several years. It jerked and pulsed at normal mid-throttle riding. Turned out to be the return fuel regulator, which sends unused fuel from the fuel pipe back to the fuel pump.