I have a 04 raga rep 300,which has started making knocking/rumbling noise from the engine.Makes no difference pulling the clutch in,performance still good.I have taken head and barrel off,bore,piston,small and big end bearings are fine.no up and down play in main bearings at flywheel side,no wear or damage in anything in clutch casing.anyone got any ideas please?

is the bike playing up? very hard to give you advise when every thing seems to be ok

You did a lot of work!

It could be some bad gas or an obstructed pilot jet.

Try opening the enrichener a little (you may need a piece of wire or a small ziptie on the rod) and see if the problem changes.

Did you take the clutch basket off ?

It may be that its chipped a tooth on the idle gear (between the back of the clutch basket and the kstart gear). This gear is in mesh all the time so it may explain why there is no adverse performance. A couple of my pro's have done it.

Baldilocks has a point here.

Maybe something is worn there, making that noise.

Mine Pro 250 2002 has a shipped startergear and the tooth was loose in the cases. Made a mess but no serious injurious thnks god.

So check the clutch innerside for anything out of order.

Thanks for your help guys,richening the mixture has no effect,have inspected all the gears in clutch casing,tried a clutch off another bike,still no difference.Have recently fitted new kickstart gear and idler gear as kickstart gear broke,but it had this bloody noise before and after doing this.I've been thinking,does the gear oil on this bike also oil the main bearings,if so could some particles from the damaged idler gear got to the mains and lunched them?It vibrates more than it used to as well.fantastic bike when its right though.

With the clutch basket off check for up and down movement in the main gearbox shaft and the other one. End float is ok as long as its not excessive.

Could be a gearbox strip down and 4 new bearings but I'm no expert.

when I had my 04 raga it suddenly developed a bad noise sounded like bad crank bearing took off clutch etc and no visible problems

noise appeared to be coming from flywheel side I did not have a flywheel puller but I am fortunate to live 2hrs from Jim Snell the gasgas parts importer.

I took my bike to him and he pulled the flywheel off and noticed the case below the flywheel had been dented slightly from a hit to the skid plate.

he pounded the case out a little and end of problem

the skid plate is a little thin so it bends easy

Maybe this will help

Tom Bledsoe

Yes, gear oil lubes the mains and at the clutch side they get the full load of particles. Try grabbing the flywheel and really push hard up and down. No, anyway no detectable, movement shld be felt. However 0.01mm more or less is the freeplay of a mainbearing so when in doubt stop driving the bike around and go for a pro to let him feel it.

Check out the topic of mine: it is a open Pro 2002 engine.

Do a search: Pro engine