Mark 78A rebuild question

[stubbstheman88]

hello
i am not new to outboards but have never done a complete rebuild before

we recent bought a 1960 80 hp mark 78a direct reverse...i know all about the reverse system and how the whole motor runs in reverse...
when we bought the motor it had been sitting on its side in a barn for maybe ten years...we opened the ports on the side where the fuel enters the cylinder and found that the top cyliner had a resident....apparently a mouse entered through the carb throat and made a nest in the cylinder and caused it to lock up...we figured the only way to fix this was to open the block and clean it all out completly...i was wondering if this was a big deal just taking the whole assembly out and cleaning it. Could this be done easily? also the plate on the back of the block with the pug holes in it....if that is taken of would that make it possible to clean out the cylinder?

any help or comments would be greatly appreciated

 

[Laddies]

Re: Mark 78A rebuild question

A critter nest is not good as the urine may have caused rusting and pitting, the only way to get to the insides of the engine is to pull the powerhead and tear it down the plate by the plugs is only a water jacket cover. Everything comes out the crank end, not a real hard job takes some time and a manual.

 

[stubbstheman88]

Re: Mark 78A rebuild question

ok thanks a lot

 

[rodbolt]

Re: Mark 78A rebuild question

I hope you dont find out why we called them"Dock Busters" .

 

[stubbstheman88]

Re: Mark 78A rebuild question

haha ya i did hear about that....could this motor be worth a good amount of money becuase of its rareity?

 

[swordfish25]

Re: Mark 78A rebuild question

I had several of those direct reverse motors, they were good when they ran, as long as the starter held up. they were tough on water pumps. Ended up with a 9500 gear shift and was much happier. I still own a 115 inline 6. I personaly would not put a lot of money in it. Time yes. Good luck