Q: I have a Honda VFR800 VTEC, 2002 model, with 35,000km on the clock that has started to vibrate above the VTEC threshold after a day on a go-kart track. There were a few visits to the rev-limiter but no violent downshifts. These vibrations are noticeable in the seat, hands and feet between 7,000 to 8,500 rpm but seem to go away above and below this, there were no vibrations before the track day.
The bike has a ‘slip-on’ silencer and the PAIR, snorkel and flapper valve modifications done by PO otherwise, as far as I know, it’s stock.
So, any ideas what could cause this and where should I start to look while trying to fix this?
Regards Toby
A: This is a difficult one without having the bike in front of us. But first take off the air-box lid and have a good look inside to see if anything has come loose, seeing as mods have been made in there already.
It might be one cylinder has begun to give problems that would certainly cause vibration problems due to the imbalance this would cause, so perhaps a compression test might be a good start. You might want to check to see if the throttle bodies have gone out of sync as well, but that would possibly mean a visit to a Honda dealer.
We’ve also heard of voltage problems with this bike so make sure the battery is healthy as well?
Hope these pointers help and maybe have a check around various forums around the Internet world to see if anyone has similar issues?
