Mercury 65 H.P 650 1973 or 1975

[JMyer30]

I have a boat that I'm going to be doing a refurb on, and I have a motor that I was hoping I could get a little information on. I'm inheriting this boat and motor, and I wanted to know if I should just junk the motor or have it fixed. All I know about the motor is that it is a Mercury 65 HP, 650 looks to be from the 70s like 73 or 75, last time it ran might have been 20 years ago give or take a few years, not really 100% sure last time it ran it was my grandfathers but he did like to fish a lot, as we all will as we get into our golden years. My father says it ran just fine last time it ran. So the question is would this motor be worth removing from one boat and put on another boat so I could have it fixed. I know it would need all new seals plugs and water pump and gear oil. Without seeing it what else could be wrong with it being that it has sat for say 20 years in the Pennsylvania. I want to know if it might be worth fixing.

 

[Faztbullet]

Check the compression first. If compression is ok check for spark and the wiring as it rots..

 

[Dmpaul89]

I have the same motor mines a 1975. Its a real screamer on my 16fft aluminum v bottom. IF you haven't done anything yet. oil down the cylinders before cranking it over! 2 stroke mix gas or any light oil will do. its a 3 cylinder motor. you'll have to rebuild the carbs and put a new water impeller in it at a minimum. IF you can do the work yourself or have someone with mechanical knowledge help its worth putting some work into. If you would be taking it to a mechanic id just forget about it, most of them wont even work on a motor that old, and if they do they'll want to replace all the wiring and hoses, that with the carbs and water pump rebuild would be over $500 repair im guessing. If your gonna sell it id say $200 is a fair price as is. I paid 350 for mine running

 

[JMyer30]

Oil down the cylinders with regular engine oil or with the 2 stroke mix gas? It will be going on a StarCraft Super Sport 18ft aluminum V Bottom. I can handle working on it, no problem, I have a lot of family and friends with mechanical knowledge, and I have been around it so long I know some things. When I oil down the cylinder just do it through the spark plug holes? How long should I let that sit before trying to crank it over?

 

[JMyer30]

Just talking to my father about motor, it was fogged after its last use. I feel this will workout for me.

 

[Dmpaul89]

That's good it was fogged, id still oil the cylinders through the spark plug holes and clean/replace the plugs. Mine pushes a 16ft v bottom 33 mph with just me, 31 with a passenger and fishing gear.

 

[Dmpaul89]

heavy mixed gas will work, or some spray can penetrating oil, not wd40