1963 75hp Evinrude Rebuild

[yorab]

Hello again. I started working on a rebuild of my 1963 75hp Evinrude about a year and a half ago, but I ran out of time and had to put the project on hold. I have the original engine plus a parts engine. I just dropped off the blocks at the shop today so that my guy can let me know how much has to be bored/honed from the cylinders. I'm going to go with the block that requires the least amount of work. I've done some research on this forum and I think I've found the answers, but I wanted to get a few bits of feedback on my specific engine before I go too far.

1) Is it okay to oversize just one, two or three cylinders?
2) If the cylinder is oversized, do the rings and pistons also have to be oversized by the same amount, i.e. .020 cylinder, .020 pistons and .020 rings?
3) I will be painting the block so should I paint before boring or after?

Thanks for the info and I'm sure that I'll have other questions as the rebuild progresses.

 

[Chris1956]

Re: 1963 75hp Evinrude Rebuild

Paint after block is reassembled. Use masking tape over intake manifold and spark plug holes.

Have you priced out oversize pistons and ring sets (You must use oversize piston and ring sets). On that old of a motor you may not find them. You can mix and match oversize piston and ring sets with standard ones w/o issue

Change waterpump impeller, clean and rebuild carb and fuelpump. Install new points and condenser. Perform link and synch

 

[yorab]

Re: 1963 75hp Evinrude Rebuild

thanks chris1956. I'll use that advice.

One more thing I'd like to understand a bit better. There is a coat of paint on the internal surfaces of the block. It is a reddish-brown color. When the block goes through the parts cleaner, I would imagine that the paint will come off. Will I need to reapply this paint before reassembly? Can anybody tell me what that paint is for? I've included a pic of the opened block showing the internal paint.

 

[F_R]

Re: 1963 75hp Evinrude Rebuild

thanks chris1956. I'll use that advice.

One more thing I'd like to understand a bit better. There is a coat of paint on the internal surfaces of the block. It is a reddish-brown color. When the block goes through the parts cleaner, I would imagine that the paint will come off. Will I need to reapply this paint before reassembly? Can anybody tell me what that paint is for? I've included a pic of the opened block showing the internal paint.

I would strongly advise against doing anything that will remove that coating. It's purpose is to discourage corrosion in the cooling system. They dip the whole thing before doing the machining operations, is why it is everywhere else.

 

[yorab]

Re: 1963 75hp Evinrude Rebuild

Okay. The only reason that I wanted the block to go into the parts cleaner was so that the new coat of external block paint would adhere better. Should I just use some engine degreaser spray locally on the external surfaces of the block where the new coat of paint will go?

 

[R.Johnson]

Re: 1963 75hp Evinrude Rebuild

Where did you find pistons, and rings?

 

[yorab]

Re: 1963 75hp Evinrude Rebuild

I haven't purchased them yet because I still need to find out from my machinist what size I will need for each cylinder. I did search around ebay a bit and found a few oversize pistons/ring sets. I just hope that they're still there when I try to buy later in the week or next week.