i got the nut and washer free from yamahathey also fix shaft if its wreckedthere is a thread about this somewhare
Would an Arc welder be suitable for doing this or would I need a mig?
I didn't measure it but I'm pretty sure it is. The nut sits flush with the end of the shaft.
if the lock washer is used it will not loosen. Simples. If the lock washer is fitted properly that is.