evinrude nitro case

[formeone]

anybody know what the gear ratio was in these cases???? working on a projecthere,,,, thanks..

[850cc racer]

Well theres a few.. Maybe someone can tell me the exact ratio i have a 2.5-1 2-1 and 1.85 ish' -1

the 1.85 -1 has a belguim i.d. Tag.

[Barry Strawn]

As far as I know all the three cylinder, 15" midsection, 75hp engines, since the small gearcase came out in 1975 are all 15:28. Right through to the end of the SST-60.

But there could be two cylinder cases or gears in use under a triple.

[formeone]

sooo same as the fishing gear cases??

[Mark75H]

Yep, it is a fishing case

[Barry Strawn]

sooo same as the fishing gear cases??

They are all "fishing gear cases" if that means they shift and have conventional through hub exhaust. The 15" 75hp models after 1975 all had a 3-3/8" diameter case with the 15:28 ratio and the 20" models all had a 4-1/8" diameter case with the 12:29 ratio.

The smaller case and the 15:28 ratio is very desirable if you are trying to go fast.

[formeone]

wow cool guys ,,, another quest,,, wich case did the old tunnel class "se" use to run?? under the 3 holer and also about what size props??? what is sst 60 running now????..thanks..

[Popa Sam]

As far as I know all the three cylinder, 15" midsection, 75hp engines, since the small gearcase came out in 1975 are all 15:28. Right through to the end of the SST-60.

But there could be two cylinder cases or gears in use under a triple.

I agree. All 15" were 15:28 and all 20" were 12:29.