New vibration problem

[phil mcglassup]

Hi All,
I have a problem with vibrations between  4k and 5900 rpm...yes that accurate  :eek

Any ideas what is wrong ? It was runnng fine until recently and I haven't changed or done anything to it. Vibrations are coming through the bars, footrests and frame / tank. The bike has no fairing and the indicators are non-standard and the carbs were balanced recently. The bar end weights are on and to improve the footrests I bolted on some steel bits at the ends...I thought that if it works with handlebars it was worth a try. Seems strange that at 5900 rpm and above it is like someone is switching off the vibes so that there are no vibrations at all.

Any ideas where to look?

[Frosties]

Drop a gear  :lol

[Graham53]

Had bad vibes on mine at similar revs recently and it was a combination of rubber on centrestand missing giving vibes from exhaust, chain being a bit dry after being laid up for long time, sorting those helped greatly but when I did oil and filter combined with resetting TPS and air filter it virtually disappeared, also what about engine mounts ??

[phil mcglassup]

Sometimes I do drop a gear..and yes, the problem then goes away !!

I took the centrestand off a long time ago but it does soon need an oil and filter change. I'll check the TPS, air filter and engine mounts. On other bikes I've loosened all the engine mounting bolts, lifted then lowered the engine with a jack, then retightened the bolts which seemed to help.

I'll let you know how it goes...thanks  :thumbup

[unfazed]

Get a 25 washer with a hole big enough to take a 12mm bolt and place it between the inside of the rear footrest and exhaust hanger.

[phil mcglassup]

Thanks for the reply but have already done that  :thumbup