Logo

Winterising OMC 120HP in Scandanavia - where are the Petcocks?

Jamie Talbot

New member
Hi,

My First post and new to new to boating this year. Id very much appreciate some more experienced advice!

I have a 21ft Motor boat with an OMC 120HP sterndrive. The engine is from around 1977-78.
Im preparing to winterize , and in an environment ( Sweden ) where we get seriously sub zero temps for months at a time i'd appreciate any tips on anything I've missed.

Im planning the following ( after much you tube research) - with the Boat out of the water an sitting on my Drive way ( full fuel tank and stabilised)

1) Fresh water flush via Muffs, once up to temperature, then
2) Shut down and change engine oil and oil filter, and also the gear / Drive oil
3) Run engine up again to get oil circulating, then add glycol mix to the water intake until the glycol is coming out of the exhaust.

So heres the first question, once the glycol is running through the system, should i leave it in or drain it out of the engine?

Second question, should i add the water through the water intake in the drive, or directly through one of the hoses?

Finally if i need to drain the glycol form the engine, where are the petcocks on an OMC engine form the late 70's?? I can find one but am told there are three.

After the above, and while the glycol is in the system i was going to fog the engine until it stalls.

Then as a finish i was planning to spray the fogging oil into the plugs and the cylinders and give the engine a turn over to get the pistons covered in the oil.

Appreciate any feedback!

Jamie
 
It is best to drain water from the motor before using the glycol.------------If you fog the motor there is no need to remove sparkplugs to add more oil.
 
Just drain it. That's what they tell you to do in the manual. Refilling isn't necessary until you recommission in the spring. You don't need to fog the engine either. Just do an oil change before you put it up for the winter.
 
one drain on bottom side of exhaust manifold towards the rear underneath. The other is on the engine block about 8 inches away down from the first drain.

After water drains, poke wire into the hole to make sure there isn't rust flakes clogging.

Then take one end of the the u shaped water pump hose off and aim it into the bilge to dump the half-cup of water out of it and reinstall it.
 
Back
Top