2004 Official factory service manual for Yamaha YFZ450S ATV Quad., Page 179Get this manual
A.CMAGNETO EBS00259
REMOVING THE A.CMAGNETO ROTOR 1Remove: A.Cmagneto cover NOTE: Loosen each bolt 14 of turn at time, in stages and in crisscross patternAfter all of the bolts are fully loosened, remove them3
2Remove: A.Cmagneto rotor nut washer NOTE: While holding the A.Cmagneto rotor with the sheave holder 3, loosen the rotor nut Do not allow the sheave holder to touch the projection on the rotor_