i,ve just discovered the same noise, but on the left side, my fly wheel crank bearing seems to be worn out, not sure on the limits of free play there.
also removed the plugs and turned flywheel by hand and got a tock tock sound coming out plug hole (LH) .so i put a plastic tube down onto the piston and turned it over TDC ,it went quieter with the pressure on piston,could some one help me with some sort of answer to this ,as i've just put new pistons and rings in 6mths ago and dont ride it much,dont want it to go on me again
adjustable timing plate,shaved head, rest standard ???
burnt hole in left piston last time,replaced seal then, replaced bearing 12 mths ago
??