TOPIC: 50hp

hi, i need to replace the powerhead on my 1971 50hp ser# 3171509. will all of the inline 4 cylinder powerheads bolt on my midsection? thanks

You will need a powerhead from 1965 onward as there was a block change. There are many other smaller differences to complicate things, especially from the early 70's but it is possible to make it work. Try to get a pre 1976 powerhead, the later engines will require mods.

thank-you sir, when you say the later ones need mods is that mods to make the cowlings work or the ignition ect?

Yes.

All of the above! Try to find a donor engine as close to your year as possible, that will help a lot. There were many changes through the years, some small some large but the basic architecture is the same and with some fiddling it can be done.