1968 Johnson SC-10S 1.5 HP Gearcase Oil

ConchPirate · Jul 22, 2020

Wondering if anyone here knows for sure what oil weight was recommended for the small gearcase of my 1968 Johnson 1.5 HP motor? I can't find any manual references, and I had to pull it apart to change the water impeller. Hoping there may be an old school mechanic here that may have worked on these small motors back in the day. TIA folks.

racerone · Jul 22, 2020

Use 90 weight outboard gear oil.-----Or HI-VIS from your friendly local BRP dealer.

F_R · Jul 22, 2020

For Sure??? Counting evolution?? In 1968, OMC made a big deal of their Type C oil, and that's what you were supposed to use in your 1.5 and everything else at the time. Jump ahead a few years, and Hi-Vis replaced Type C in everything except Electric Shift models. So then you were supposed to use Hi-Vis because of the high load put on gears with the introduction of the Horsepower race. Jump forward to now, and it doesn't really matter. That little motor is very forgiving and never entered the horsepower race. Bottom line is any 80-90 wt Outboard Gear Lube is just fine.