rb rasping noise at high revs ......

[rocho68]

mates rb has a rasping noise when he hits 5000 revs then vanishes when it goes past 6 , no loss in power , only thing hes changed is the exhaust to a franspeed race from an nk in the last few weeks , has anybody else experienced this and could it be the reeds ????

[jonashford]

Mine rattles like bugger, prob piston slap, the r6 shocker spring vibrates as well

[nelson pk]

Not an expert by any means on the RB but if you have changed the pipe, did you check the jetting?
Is it rasping at a certain throttle postion (for example full throttle) at 5000 revs or at all throttle positions at 5000 revs.
If its just one throttle position it's very likely to be jetting. Different exhausts can created big differences in jetting.

[tj hooker]

keep it past 6000rpm then he wont hear it

[lamy150]

nice one tj,

just removed the sr 190

[coaster]

Difficult to say without hearing it but it could be something vibrating atr a particular frequency. As the exhaust has been changed I'd look there first, check the fan/head cowling is fully secured and is not vibrating on the stub or expansion chamber anywhere or maybe the rear runner?

[Stampede]

Check you jetting first. Rattling of an loose part can´t wreck your engine, but a lean jetting will do it very fast!