1969 Merc 800 thunderbolt (80HP) rebuild

[frabcabert]

Had lots of issues with my outboard last fishing season, so i decided to do a rebuild on it. Figured I would post this with some pictures, experiences, etc. for all of you just wondering whats in that powerhead.

 

[frabcabert]

Re: 1969 Merc 800 thunderbolt (80HP) rebuild

Lower Crankshaft bearing fell into pieces as soon as I had opend the block. Some of the bearing got under the lower piston, damaging it and pinching the rings on it.

 

[frabcabert]

Re: 1969 Merc 800 thunderbolt (80HP) rebuild

 

[frabcabert]

Re: 1969 Merc 800 thunderbolt (80HP) rebuild

Well I got the boat out on the water this summer. Once.:facepalm: anyway. It worked great for the first day of fishing, the motor would still stall when I put it into gear, but not nearly as easily as i did before. Then out of the blue it lost power. Didnt die, just had a heck of a time getting it onto plane. I do have a bad sparkplug wire, and my distributor cap was very coroded. I'm thinking that this is my issue, what do you think?


Here is a short clip of when it worked