Hi Guys

I am hoping someone can give me some advice as to what could be causing what I would describe as excessive vibration from the engine on my 2007 Rev 3 250. The bike always starts and runs fine but I have noticed for some time that there is excessive vibration felt through the frame/pegs which gets increasingly worse at higher revs (both in gear and neutral) which is particularly noticeable when riding between sections.

When I bought the bike the waterpump seal had been changed by the dealer but I found that the coolant was mixing with the gearbox oil. When I investigated I found that the replacement seal fitted by the dealer was not seated properly in the housing so I replaced the seal and since this time this issue has been cured.

My fear is that when coolant was being lost the bike could have overheated and I am wondering if this caused the vibration problem as I do not remember it being an issue when I got the bike.

Any suggestions as to potential causes and anything I should check would be much appreciated.

Check the engine mounts, especially the rear, and also the bash-plate bolts, before you do anything else.

+1 all the engine mounts and ...... + exhaust mounts and...... +frame bolts

My mate had vibration through the footpegs and it was his main bearings.

I have checked all the engine mounts and they were all tight so looks like I am going to need to strip the engine down and check the main bearings. Many thanks for your comments I will report back my findings

I had the same issue with a YZ250 crosser. It was a very old tired dog when I got it (1995). It was a cheap scare myself bike until I had the same as you. An obvious thumping through the frame and footrests. I called it a day and stripped the motor. Very glad I did as the big was seriously slack.

Re built with new bearings etc the bike gave me many years of good service and abuse.

im having similar issues of excessive vibration with my 270 Beta, It also had water pump failure and severe gearbox contamination.

this is all fixed now but compared to my 125 sherco the vibration is very noticeable.

can anyone else confirm if replacing the mains cures the problem? are the expensive to buy?

Cheers

Matt