Re: 1956 Bigtwin 30 hp
I brought a 30hp bigtwin back to life several years ago. Here's what I did:
(Assuming compression is good)
1. Rebuild the carb.
2. Inspect/replace any questionable fuel lines.
3. Pull the flywheel and clean and set the points - better yet, put a new set of points and condensors.
4. Inspect the coils - replace if cracks are evident.
5. Inspect ignition wires - replace if required.
6. Pull the lower unit and replace the water pump impeller.
7. Change the lower unit lube. If lube is milky - fix leak in l/u.
8. Give any grease fittings a fresh shot of grease.
9. Fire it up
I think this covers the basics, assuming there are no significant mechanical issues.
Mine ran great after I did this. Unfortunately, I sold the boat I ran it on. It has been sittin idle the last 5 yrears. My wife keeps asking why I'm hanging on to it. I keep telling her I have plans for it in the future when I retire up north on a lake. She keeps telling me I'll be on my own "up north on a lake". At least I'll have the old 30hp to tinker with and keep me company.