Any problems with 1965 Merc 650 motors?

[wishboneZ51]

I have a really nice 650 that came with my boat and I want to keep the boat origional with the engine it had on it. I was just wondering if there are any little quirks with these motors or anything that fails on them quite often? I need to do a compression check on the motor, but I do know that a lot of the wires are heat cracked and will need to be replaced. Where can I get the outside wireing harness that plugs into the motor that is in good shape?

Thank you for your help gang.

 

[Fuzzytbay]

Re: Any problems with 1965 Merc 650 motors?

The biggest problem with older merc motors in general is cracked wireing.
First do the usual tests, compression, look if the motor seems to have been pulled apart, check the bottom end oil, look for visable signs of running into hard objects at high speed etc. If all thats good, and all thats left is a new rewiring job, its pretty basic. As for the plug, you might get one on e-bay, or craigslist etc. or if you can save 6 inches on the old one, just rewire butt splices on it, use heatshrink and rubberized electrcial tape, and you should be good to go.

 

[wishboneZ51]

Re: Any problems with 1965 Merc 650 motors?

That is great to here that the motor really has no problems. The first things in order are to check all of the sylinders for compression. Next will be to check spark for each plug.

Are there any problems with the ignition system that I should be concerned with? It looks like it has a cap and rotor system on it, are those systems ok?