Re: Merc info needed

[20mercman]

quote 20mercman:

The motor is a 1955 Mk-25 as has been posted. These are very popular with the Mercury folks, and were a significant upgrade from the Mk-20. These use a Phelon ignition system that is very reliable. It will most likely be in need of a rebuild on the magneto as the coils will be bad if they have not been replaced. I would also recommend the condensers be replaced at the same time. The lower crank seal may also be ready for replacement by now. (it’s 61 years old!) These are very nice running motors. Like was posted, they are fairly straight forward to work on. I have built 10 of these, and I don’t have any real special tools except a tool I made for removing the water pump cover and the gear case cover. A high quality spanner wrench will often work if they are not badly corroded in place. Lower unit seals and really anything on a motor of this age should be checked and make sure they are in serviceable condition. These will easily outrun our 1956 FD-10, but they are a bit louder. Very compact design for the 18-20hp range motors. (55 were rated at 18hp, 56 and later were 20hp, but really the same motor.)

This particular motor looks very good for being an original. I would not hesitate to add this one to my collection as it has certainly been well cared for. Any motor that you want to be reliable no matter who built it should be renewed to make them dependable. These were OK’d by Mercury to be run on 50:1 as they were “Full Jeweled Power” (Roller and needle bearings on all bearings)

Ask any questions.

Steve

Edit: I agree with Bill that pushing a larger hull, you would be much happier and so will the motor with a 3 blade 9P prop vs. the 11P that is on this motor.