TOPIC: 1954 Mark 20

Can anyone tell me what the proper lowerunit gear oil is for this motor? This is my first vintage Mercury so i,m still learning. Thanks

www.fiberglassics.com/glassic-forums/mercury-outpost/recommended-lower-unit-lube-oil-question#3779Some people will tell you to run nothing but Mercury gear lube, others will say any good brand is okay. Personally, I run a name brand and pay the extra for the synthetic version. (I figure it to be added insurance, lube is cheaper than gears, bearings, etc.!) Just MHO.

Welcome to FG, btw! (Our regular greeter is off-duty this weekend, at a boat meet. How am I doin', H?!)

I personally would be running Lubriplate 105 from Napa in that lower unit. It's a white grease, not oil based.

store.eastcoastmarineservice.com/category_s/489.htm

This is what Merc called for.

I have 3 Mark 25's, 2 KE4's and am getting ready to pick up a 1949 KF5. All run lubriplate.

I'd also strongly encourage you to reseal the lower unit with new seals if it's not been done.

Do you have the pressure tank for that motor, or did you convert it to use a fuel pump? I like the Mark 20's, but the 25's have a fuel pump and don't take that mucho expensive pressure tank and Mark 20 engine fitting, look similar and have the Phelon coil system.

If you need have the pressure Tank, John McIntosh has the rebuilt parts for it.

www.johnsmcintosh.com/Parts.htm

Whew! Thanks for bailing me out on that one Dan. Maybe I'd better stick to playing with my Johnson. (motor)

I run Lubriplate 105 in my 40's & early 50's mercs

Thanks for the info i'll be sure to use the right stuff when I change it.

i agree with lubriplate 105 but i change it every year.