1973 Merc 7.5hp lower end unit question

[Biggyniner]

I just bought an old 62' boat with a 73' 7.5hp merc on it. I was curious as to how much gear oil needs to be in the lower unit?

Thanks

 

[Downrigger]

Re: 1973 Merc 7.5hp lower end unit question

I just bought an old 62' boat with a 73' 7.5hp merc on it. I was curious as to how much gear oil needs to be in the lower unit?

Thanks

I would suspect very little since my 15hp only takes about 6oz.

 

[emckelvy]

Re: 1973 Merc 7.5hp lower end unit question

If you go to Wally's and get a quart of Hi-Vis marine gear oil (about 3 bucks), you'll have 2 or 3 season's worth of oil changes for your Merc!

If you want to really splurge, pick up a hand pump which fits in the bottle and makes it way easier to oil up.

You have enough oil in the lower unit when, as you're pumping oil thru the drain plug hole in the lower part of the gearcase, oil is rushing out the small vent plug hole, at the upper part of the gearcase on the side.

After filling, reinstall the vent plug first; this'll prevent oil from gushing out the drain plug hole when you reinstall the drain plug.

HTH & Happy Boating...........ed

 

[Harker]

And don't give it a quick pump after putting the vent screw back in! You'll blow the seals on the top of the unit. Been there done that....