Originally Posted by spaceworm

I guess I need to ask what the diameter of the engine's prop shaft is? If it is 10mm, why is the safety nut 13mm? Could your safety nut be I/2 of the locking prop nut used on Saito engines. My engines have a special nut that tightens against the prop washer. Then a special tapered split cone type nut is tightened against the first nut. The split taper and nut act as a collet to lock the nuts together. But, I could be way off base here,