Transmission noise.

[Alvinmotors]

I am quite a new owner of a Moto Morini 350 Kanguro X2, which is running perfectly ok, however with following exception:
On ‘throttle off’ (engine braking) there is a noticeable transmission noise (in any gear). I first believed this possibly come from the chain idler roller and made a new one with a proper sprocket (which seems to be a good modification), but this didn’t solve the mentioned noise in question.
Has anybody experienced the same ‘throttle off’ noise problem?
Could this be created by axial play in the helical gear primary transmission? (I have not yet opened up the engine transmission cover.) If so, which is the best method solving this?

[Steve Brown]

Is it a dull sort of whining noise? A friend of mine has that with his recently rebuilt Kanguro. He's tried different roller combinations too. I'll have to ask him how his is doing now. I wonder about the nylon slider on top of the swing arm pivot area-it's made out of some sort of nylon that goes off/brittle with age/UV etc. Most of them I've seem are chipped broken and of course no new ones are available.
Now, who do we know with a 3D printer that could possibly make a few for us?

[jfh]

Could you use a piece of a nylon chopping board!?

[Alvinmotors]

Yes, it can for sure be described as 'a dull sort of whining noise'.
My next step will to put on a new chain and chain sprocket.

[44dwarf]

I get this in 2nd gear only, but the last two racers have told me they had it as well. not making chips in the oil so it can't be too big of an issue.