What size is this missing nut?

[Christian68]

Hi,

I have a 1983 Evinrude 35 HP. I noticed this weekend I have a missing nut on the lower end. Attached is an example picture of which nut is missing. I believe it is part number 0306422. Does anyone know what size and thread it is? That way I could get one from my local hardware store.

I tried a 5/16-18 that I had and it did not work. Therefore I think maybe it is a fine thread 5/16"-24. Unless it's metric.

Thanks.

 

[tphoyt]

Off the top of my head I want to say 5/16 24.
Best

 

[clemsonfor]

If a 5/16 course started to thread or is very close in size but didn't work it's fine thread. There SHOULDN'T be any metric nuts or bolts on that engine.

 

[Christian68]

Thanks guys. It was in deed a 5/16-24 fine thread. Good to go!