1978 Johnson 75 HP 3 Cylinder Water in crank and rust

[msr64555]

Hey all, I have torn apart my first 2 stroke motor due to getting water in the cylinders somewhere, and I figured I would replace all the gaskets if everything looked fine internally and call it a day. It looks a bit worse than I had hoped (at least from my limited knowledge) on the inside and would like to see what ya;l think about cleaning this up if it is worth it or not. I am not looking to do a rebuild replacing everything because I know it is simply just not worth the money on these older engines and it will be much cheaper to repower than rebuild. So just looking for a bit of guidance from yall on these pics and if you think this thing is savable without replacing the crank/rods/pistons or not. Thanks in advance!

 

[faztbullet]

Cant tell till you remove rod caps

 

[racerone]

Agreed----Take rod caps of.----Tane main bearings off.

 

[msr64555]

Cant tell till you remove rod caps

Got the bottom cylinder out, which is the one that looked the worst. Here are a few pics of the needle bearings and the rod/piston.

 

[msr64555]

Agreed----Take rod caps of.----Tane main bearings off.

By the main bearings do you mean the bearings at the ends of the crank?

 

[racerone]

No----The 2 in the middle.

 

[racerone]

And where was the rust you saw.-----No evidence of damage that I can see so far.

 

[faztbullet]

Clean it up, hone cylinders and install 3 new Wiseco piston as they like a sloppy bore

 

[fdrgator]

Those motors are well known to have water intrusion coming from leaking exhaust covers. The plate is very thin and warps from exhaust heat, and the gasket no longer seals.