advise on buying a engine

[daniel9829]

I need advise. I am buying a used boat with a 850 Mercury on it 1994 model I will be pressure testing the cylinders. Is there anything else I need to check on?
Thanks in advance

 

[saumon]

Re: advise on buying a engine

First thing, wich one is a 1994, the boat or the engine? (hint: there's no such thing as a 1994 850; in 1994, they're 75hp and 90hp). And what boat are you talking about? Anyway, it's always highly recommended to do an ?on water? test.

And welcome here too!

 

[Don S]

Re: advise on buying a engine

850's are from the 70's. When you see that type setup, you can bet the engine was found cheap to make the boat runable so it could sold to some unsuspecting person that doesn't know what year it is.
Those old engines ran good, but some things are NLA, and the wiring has a bad problem of the insulation cracking and falling off. Keep that in mind, and be sure to do an on the water test and go to WOT to make sure it will get there without falling on it's face.

 

[daniel9829]

Re: advise on buying a engine

Thanks for the information. I was about to ask that question after doing some research yesterday afternoon I soon discovered that Mercury did not make a 850 in 94. I will be asking more question to the owner of the boat this afternoon. We are set to take a test ride for about 30-45 minutes.
Again thanks for the information.

 

[daniel9829]

Re: advise on buying a engine

Ok we took the boat for a test drive and this is a 1977 850 mounted on a 1994 Sundance 17 fr center console. The boat ran out to 32 mph by my gps and cranked right off the bat. the owner states he uses the boat nearly every weekend so I believe it has high hours. He is asking 3100 for the boat and motor trailer is in good shape galv. this seems reasonable but I really dont know and this is my first boat.
cyl heads run around 115 on compression test Highest 120 and lowest 110. thanks for any advise.