Old Merc Lower Unit

[Hipfan34]

I bought an old merc 1966 500 (50hp,4 cylinder) and it has'nt been going for a couple yrs or more.

The lower unit had no oil in it,i was wondering if there was something i could use to flush out the gear case before I put fresh gear oil in,and attempted to start it.

Thanks

 

[Chris1956]

Re: Old Merc Lower Unit

You could try regular motor oil, and let it sit a day or so, before draining. I don't recommend actually running the motor on non-gear oil. You also might like to drain out the new gear oil after a trip or two and refill with new gear oil. It should get more of the dirt (if any exists) and you can check for water intrusion.

 

[tashasdaddy]

Re: Old Merc Lower Unit

put some diesel fuel or kerosene in it. rotate the prop by hand a couple of time every 10 minutes, drain after 1 hour, and install grease. always use new washers on the drain and vent plugs, when removed. these are the #1 cause of water getting into the lower unit. then take for an run and check for water the next day, allow for it to settle out. water will be on the bottom.