I checked the compression and its hitting above 90 so I can say the block is good but it will need points, coils, and condensers replaced. As of when it last ran I couldn't tell you.
Your most welcome Winchester, matter of fact I have a 1958 or 57 35hp Johnson Super Seahorse in the shed. Kind of a rebuilder but all of the parts are there from cowling trim to engine parts, so if you need some thing just let me know and I can help locate/chase parts.
I have no problem with working on the Johnson...I've been E/J Mechanic for the past 37 years. I just have to come up with some parts for it. There will be some somewhere. My guess is this engine came on this boat from what I can see. Merc is OK - I'm just not a Merc mechanic.
Have a brother about 21/2 miles east/SE of Will Rogers...small world!
drop the motor, get a good one, I have a friend here that specializes in the old motors, he has a couple good marks, cheap, and he ships. Dave 405 - 769 - 1601 been doing with him over 20 years, and he Is a perfectionist.
Dolfin Marine is his business give him a call, but don't mess with No motor some one else has Messed with, takes all the fun out of Boating.
Customer has a very nice '58 Johnson 35hp - gold and white - on this boat right now. The problem is that someone was working on it - and I use the word 'working' very loosely - and has done more damage to it than good. Outside of engine is very clean. Inside should be. Whoever, broke the top of the threads off the crank as far down as they go + I believe it has the wrong carb on it. Intake manifold has an extra hole in the flange area where it mounts - but the carb don't. So far, we have looked for a carb, a powerhead or a crankshaft only - but haven't had any luck so far. On the crank, they drilled it - cobbled a piece of ready-rod cemented with JB Weld, and a nut to hold the flywheel on! A real piece of work!
Any suggestions?
Customer is looking for a re-power to get the boat on the water for this season, and we can always put the Johnson back on it at a later date. I don't know if the boat is original, or re-done - but is a head-turner also.
a Mercury Mark 55 - 35hp or a Mark 58A 45hp would be a period correct motor for that boat, but double check my rememberer, it don't work as well as my forgetter
I advised the customer to try to find a 40 or 50hp, as I had thought that would be somewhere in the range. My Trade-In Guides provide a lot of that information, but don't quite go back that far.