1984 Yamaha 70 BETO prop shaft thread size and pitch?

[netsomnia]

Does anyone know the 1984 Yamaha 70 Beto Prop Shaft Thread size and pitch? I ordered a stainless steel prop and nut kit including thrush washer and spacer. Unfortunately I will still need a washer and the nut will not thread on past the cotter key hole. I suspect the nut is the wrong size at this point but I am not sure. Has anyone been through this? Should I start counting the threads on the shaft and go shopping for a new castellated nut? I lost the original one or gave it away.

 

[netsomnia]

Re: 1984 Yamaha 70 BETO prop shaft thread size and pitch?

I checked the prop kit part number that my mechanic and prop dealer ordered for me and it matches iboats:
70 (6H3) 1984-1995 18-3781 9-73991
6H3 = first 3 digits of the serial number on my Yamaha 70BETO outboard. Should I keep trying to thread this thing on or think twice? I am also missing the washer plate and left wondering if I can just go to the hardware store to get a nice steel washer to make this work.

 

[netsomnia]

Re: 1984 Yamaha 70 BETO prop shaft thread size and pitch?

Found the nut in the FSM - it is an M16. I will try to pickup a nut from the hardware store to see if it fits. If it goes on too tight like the one I bought then I will know that the shaft was re-threaded at some point, I can only guess at this point?