1966 Merc 50 Frozen LU

[Haven Lake]

I want to leave my boat and motor on a trailer this winter and need to know how to drain/winterize the lower unit. It rarely gets cold for long here in Seattle, but one year my dad left the engine on the boat and when he fired it up in the early spring, he found a cracked lower drive unit. I don't want to make the same, expensive mistake.<br />This engine has only been run in a small lake and still runs like it's brand new. Many thanks in advance for your advice.

 

[Clams Canino]

Re: 1966 Merc 50 Frozen LU

Drain the lower unit and refill it from the bottom hole till the lube comes out the top. (squeeze tubes work good for this).<br /><br />Make sure the motor is trimmed all the way down during storage so that the prop area can't fill with water and freeze. Some people bag the bottom for extra caution.<br /><br />-W

 

[Chinewalker]

Re: 1966 Merc 50 Frozen LU

To add to Wayne's comments - the upper vent hole is the small, round-headed screw - NOT the 1/2" wide slotted nylon screw marked "flush". That one is for adding a flush attachment on saltwater motors. The bottom drain screw is on the underside of the gearcase bullet, near the front. <br /><br />- Scott

 

[tmcalavy]

Re: 1966 Merc 50 Frozen LU

After you do the aforementioned LU service, trim the motor all the way down and wrap the LU or the whole thing in some insulating material. You know best how much, since you know how cold it may get the likelihood of how long it will remain cold. Just insulate it like you would protect a water pipe/faucet if it will have to winter over outside. That's the best insurance.