What gear lube weight?

[David Young]

Took our 15 foot boat with a 1977 70 horsepower Evinrude motor out for the first time today. I 'think' it ran good. I don't have a speedometer but i have a tach. It ran 5400 RPM on smooth water, is this good? I want to change the gear lube, i know it holds 22 oz but i can't find the weight. What weight should i use? Thank you all for your help.

 

[F_R]

In a generic oil, 80-90 weight outboard gear oil. Or some good stuff, Evinrude Hi-Vis from a dealer.

 

[jrs_diesel]

The modern Evinrude HPF Pro works well too.

 

[flyingscott]

5400 rpm is perfect for that motor. The 22 oz is how much the lower units holds not the gear weight any of the above is a good choice.