Gear Oil for 71' 115 merc

[Tinlizzy]

I just picked up a boat/motor combo with a 1971 115 hp merc tower of power.
I want to change the gear lube...I do not have a manual for it, and the only brand motors I have ran are johnny/rudes.


What brand/weight should I use? Thanks in advance.

 

[emckelvy]

Re: Gear Oil for 71' 115 merc

If you have a local Wal-Mart, go to their boating section and pick up a quart of "Hi-Vis" Marine Grade gear oil. Just a bit over $3.00/quart, you probably won't find a better deal anywhere. Otherwise your local marine shop or some auto parts stores will carry Hi-Vis oil.

Your Merc should take around 22-24 oz and if you pick up one of those hand pumps that'll screw into the oil bottle, it makes the job so much easier than those doggone squeeze tubes of oil !

Be sure to check the drain and vent plugs' fiber washer and renew if not in good condition.

HTH.....ed

P.S. if you haven't done so already, renew the impeller unless you know it's been recently replaced.

 

[Tinlizzy]

Re: Gear Oil for 71' 115 merc

Thanks for the reply em

Impeller is new according to the seller. The tell tale seems to be shooting fine.

 

[Tinlizzy]

Re: Gear Oil for 71' 115 merc

Also what should my WOT rpm be for this motor?

Hopefully I don't need a new thread

 

[diaric]

Re: Gear Oil for 71' 115 merc

4800-5300 rpm