BigBendFishing.Net

Just changed the lower unit oil, however when I went to Wally-Mart the only Penzoil they had was with the pump. Well I already have the pump so after letting drain real good I put in Lubrimatic synthetic blend.. ? is this a problem.

Power Pro 80w/90 Lower Unit Gear Lube

A synthetic blend gear lube that protects high-performance lower
units in extreme operating conditions. Highly recommended for all
engines over 100 hp. Meets or exceeds API MT-1 and GL-5 ratings.
Will not void manufacturers’ warranties.

Well I only have a 70 so is this OK.

What did the OEM spec out for it?

All the manual shows on-line is Hypoid Gear Oil (SAE 90).. I check the manual at home and see.

As long as the weight is the same and the OEM doesn't say anything bad about synthetic oil, march on. I have been using synthetic and synthetic blend oil in my vehicles for a few years now. Run regular oil in the bateau

Ds, not this is relevant to your topic, but have a question on where you got your manual on line. Bought my boat used and the only manual I could fine was at West Marine. It was a Yamaha manual that covered a wide range of different horse power and years. Useful, but would like a manuel just for my particular motors. I've found sites where you can order one, just have not done it yet.$$$ If I can go online some where to look every time I needed too, that would be cool. Thanks

Its not a maintenance manual, its the owners manual the comes with the motor. Go here... http://www.yamaha-motor.com/products/su ... otb&cid=20 choose the type engine HIGH/MID/Portable then on the parts and service tab you can view the owners manual.

Thanks

I have run the syn. 80-90 gear oil and 10-30 motor oil in my 40 Yammy since new and it has performed admirably

Thanks wevans..