1976 Mercury 65 hp first start in 12 years

[DaveS8984]

Hello,
Ive just aquired a 1976 65 hp Merc. I am looking for any tips/advice on what I need to do before I try to revive this thing. Only thing ive been told is run marvel mystery oil in through the spark plug holes and turn flywheel a few times and sit overnight. Can anybody else tell me what I should do? Also in the same deal I got a 1982 Johnson 70 hp that hasnt ran in 5 yrs. Same thing, any tips/advice that should be done before I try to run these motors? Im fearful of stuck rings or scoring the cylinder walls. Thanks a bunch

David

5 of 100

[terry taylor]

That,s good advice or fogging oil. When things seem to be freed up spray fogging oil into carbs to lubricate crank and rod bearings thanks

[tj309]

Is that Merc 65 and Johnson 70 15" shafts? If so there will be alot of takers for those motors for such things as GW Invaders and such.

Yes just get some oil in there and turn them over by hand or briefly with a battery. Make shure the carbs are clean and put that 50-1 mix in and they will probably fire right up!

[DaveS8984]

thanks for the replies. Question, what about the oil in the cylinders? Will it burn when the engine is started/running? or should I turn the motor over a few times by battery without plugs to try and get the oil out? Also any recommendation on plugs?? the engine doesnt currently have any plugs to reference. Thanks

[tj309]

Use 2 cycle oil in the cylinders and it will burn out when you fire it up.

[DaveS8984]

what about the marvel mystery oil thats already in it??

[tj309]

Dump it. Lay the motor on it's back and let it drain out.

[rock]

Before you start either, and I emphasize the word before, change out the water pump impeller. Especially if you fear stuck rings and scored cylinder walls.
Rock

[Mark75H]

Water pump impeller, fuel pump rebuild, replace the carb float needles & seats, inspect the floats. The yellow ones are most susceptible to swelling and cracking; black ones are the best. Bad crankshaft seals top and bottom are common

Check to see if the motor has a top water outlet on the block. These are prone to steam pocketing at the top, the top water outlet cures it.