Hi all,

When moving in first or second gear and then the throttle is closed, there is a strange rattling sound coming from the engine/bike. It’s not present at standstill when reving the engine.

It sounds like a loose baffle however I’ve checked them inside the silencers (Tyga) and they seem firmly in place. I have the R2J expansion chambers.

Any suggestions what may be the issue?

Any info appreciated.

Have you checked the transmission?
If it only makes the noise when moving its more likely to be a chain or gearbox noise.
Start with the chain and sprockets and behind the sprocket cover, it might be a stone rattling around in there.
Also you might not be able to hear it when going faster, in in >2nd gear.
Its also worth draining the oil and dropping the clutch cover off, check for metal in the oil.

Thank you for your response. I will check what you mentioned.

Does anyone know if the mc18 R2J expansion chambers have any internal stingers or perforated sections?

In the high pipe MC18 R5K / R6K there is an extra stinger or restricter tube in the silencer, I had one come loose and I spotted it sticking out the end of one of the pipe slightly, so I managed to pull it out. The pipe in the other exhaust took a bit more effort to remove, ie a big hammer probably. It was a long time ago, probably 2002ish..... It didn't seem to make much difference to the sound or performance?

Is it clutch rattle maybe or RC valve petals loose?