[quote=Graham, G4FUJ]Alternator.
Graham, do you eat Haynes manauls for breakfast?
Only on Sundays rest of the week it's 3 wheatabix
I had a quick look on the interweb and it wasn't clear, thank G, seems a strange part to repair , I assume its being replaced and MMC were trying to get to the cause of the problem.

Haynes, not often, I'd be getting things wrong more often than I do now...
Wheatabix? I think I'd rather eat the packet (or am I confusing this with Corn Flakes

).
John, stators do fail occasionally. If we were looking at a car engine, we'd just swap out the alternator. But on this engine, it's a bike engine, the 'alternator' is within the main engine cases (not crankcase, but under an outer cover normally).
Most bike engines that I've worked on have the rotor on a spur directly connected to the end of the crankshaft, so the rotor turns at engine speed. Sorry, not a great explanation - it's easier to draw on a piece of paper...
While not common, stators can fail - a winding in one of the coils may go open circuit or could go short circuit within a coil, thereby reducing the output from the alternator. If there is misalignment, the stator coils could be damaged by the rotor...
I guess what I'm trying to say is that the alternator (rotor and stator) are within the engine cases on most m/c engines, whereas on most car engines they are in a separate housing, belt driven from an accessory belt... Does that help?