Information on fitting N15 primary outer

HI
Finally got the clutch alignment sorted and am ready to close up primary. Any tips on how to check air gap on the alternator?
I have placed two wraps of green painters tape on the rotor, which is .012 thick and the cover goes on with out the stator marking the tape with drag marks. I have not yet rotated the rotor with the cover on.
Thought I would ask the question as I am riding today on the atlas and won't get back to this till Sunday.

Thanks in advance

Mark

Never mind, went to the AJS/Matchless forum and found the answer. Duh!!

Hi.
On my P11 i have grinded the rotor 1/2 dm.
Piero