70's Mercury 850's - can I get the skinny?

[ShoestringMariner]

So I'm considering buying a bigger boat and it comes with a 70's Mercury 850 with no spark in 2 cyls.
It looks a bit tired and I'm very leery.

Generally speaking, are these motors pretty tough? They seem to be everywhere
Are they worth rebuilding if tired? Are parts readily available still?

 

[jimmbo]

They were good engines. The basic engine has been around since 1969, and that was mainly based on the design from the 1949 K-9 engine, which was basically 2 of the old Why would you want to buy an engine that looks tied, and only running on half off the cylinders. Worth rebuilding? Based on what it will cost versus what it is worth. In one word, NO. As you said they are everywhere. Look around a bit, I'm sure you'll find one or two that are 'cherry'. BTW, the 4 cylinder 850 was made 1973 - 1977.

 

[mercurymang]

I happen to have a '75 850.

 

[ShoestringMariner]

Thanks Jimmbo. I am interested in the boat mainly. He wont sell without the motor, so I'm trying to gauge whether it's a motor worth digging into