Hey, occasionally when cranking I'll hear a metallic 'chang' type noise come from the gears that link the starter with the crank. It doesn't seem to happen continuously - but then... I stop cranking pretty soon after hearing it .

I had a look at the gears and the big one that drives the gear on the crank has some fresh marks on the outward surface (i.e. the surface facing you if you're looking at the gears in situ)... I'm not sure how this could happen

The battery may have been a little flat (I've started other bikes with far flatter batteries) when this happened - could the resistance from the engine be overpowering the starter motor and forcing it 'backwards' or popping a gear 'out' and skipping a tooth (presumably this how these gears lose teeth? Mine have all there teeth tho.)?

Not sure if this was every time I heard the sound, but I was heavily choking the air intake (to draw fuel through the carbs) - could that have something to do with it?

Cheers

If the battery is a bit flat the engine can kick back making a clang or if the starter clutch is on it's way out it could do this too.

Bleh... I had it again last night (just once) with a fresh charge on the battery