1972 100 hp Johnson

[tbrooks1015]

I recently picked up a boat with a 72' 100 hp Johnson on ithe with the hydroelectric shift. I replace the gear lube in it with Mystic jt-4 High performance lube but then I seen that it needs Type C. Is this gear lube an adequate replacement? It says it is a replacement for Type C, but am unsure if it's still suitable for the hydroelectric.

 

[oldboat1]

Here is a copy of the 12/75 service bulletin: http://forums.iboats.com/filedata/fetch?id=6973782 . Google OMC Premium Blend gear lube. (Readily available, and will tell you on the bottle that it's for electric shift gear cases.)

 

[tbrooks1015]

Thanks, but I already read up on all that. I know there's other options out there as well because I've been searching this site. No one has the omc lube near me. Was looking for something I could pick up locally. I've read that I can use Dexron ATF fluid, which is available and I believe I can use the quicksilver high performance gear lube with the yellow label which I did find locally. I was just wondering if anyone knew about the Mystik stuff before I go buy more lube and drain it.

 

[oldboat1]

Whatever you buy, look for reference to use in electric shift gear cases. Viscosity will be similar to ATF, thinner than 85/90 wt. lube.

 

[jimmbo]

Type C(speced Electric Shift) and BRP Premium Blend are about it. Mystic jt-4 High performance oil is not for Electric Shifts. The ATF option was stated in the manuals as for "emergency only". I have never seen a clarification as to what an 'Emergency' was. I wouldn't use it if I had an Electric or Hydro-Electric shift

 

[F_R]

Confusion arises because "Type C" was used in ALL outboards made by OMC regardless of size or shift during that time period. Yes, the 80-90 gear oil will replace it in all but the electric shift models which still specify Type C or BRP Premium Blend.

Having said all that, the Hydro-Electric is more forgiving than the earlier spring-clutch electric shift models. What you've put in there probably won't damage it, but might cause shifting problems under certain conditions.

BTW, iboats has Type C.