1973 80hp merc shutting down at high speed

[wemertz]

My 80hp outboard is occasionally shutting down when going at high speed. Then when trying to restart, it acts like the battery is dead. Then sometimes it will turn over and fire up. Could a bad stator create a condition like this?
When testing this out on land and the engine quits on its own, it seems like the battery is dead or the engine is frozen up and the starter is laboring against it. I do not know how best to describe it. It doesn't seem like the starter is part of the problem because the engine was already running when it all of a sudden quit. I'd appreciate your thoughts on this and what I might try checking.

Thanks

wayne

 

[Chris1956]

Re: 1973 80hp merc shutting down at high speed

Wayne, I know they made a '73 Merc 850, but did not think they made an 800 in that year also. Does your motor have a distributor? What is the serial number?

Your issue sounds like an overheat condition. When was the last time the impeller, wearplate and gaskets were replaced? I recommend a compression test to mkae sure you did not damage the rings/pistons. Post results.