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

[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.

[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..

[Mark75H]

Mod 50 used various lower units. In Europe they started with the X-115 type. At the end they used a special unit made just for them that looks like a very raked Speedmaster. SST60 uses a nose coned lower unit derived from a fishing lower unit.

[Popa Sam]

SE ran the same 15" gearcase defined above. The SST60 gearcase is the same internals with exception of the sliding clutch. The 60 housing has a larger skeg both length and chord length, it has a nose cone and only two water pick up holes on either side. The other gears that will fit in the 15" case are the ones made for the 2 cylinder motors. The gear ratio of those are 12:29. As I ask one time before, where did you get 2:1 gears for this unit?

Most of the 60 racers use 12.5-12.75 x 22-24 props.

[850cc racer]

well over here 2-1 seems to be common? i think the stingers over here came with them? i have seen about 4 or 5 in the last few years?

i dont think part numbers are stamped on gears though?

[Popa Sam]

well over here 2-1 seems to be common? i think the stingers over here came with them? i have seen about 4 or 5 in the last few years?

i dont think part numbers are stamped on gears though?

How many teeth on pinion and forward??

[Fast Fred]

The Super Nitro, not many made:eek::cool:

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[Fast Fred]

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[Popa Sam]

The Super Nitro, not many made:eek::cool:

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Nitro gearcase with a nose cone, dime a dozen(merely a figure of speech). SST60 cases are the ones that's getting scarce.

[Fast Fred]

gots this one hear, changin it out for a Super Nitro, maybe up for grabs, maybe a backup unit.:cool:
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[Popa Sam]

It would not be legal in SST60 due to water pick up mods. That's the trouble with many of them, they would be good cases if not modified.

[formeone]

cool info... for the techies since ive never counted the teeth when i had one apart is the reverse gear the same number of teeth??? in case i wanted to lock in reverse and put a different rotation prop on it???

[Fast Fred]

ya not runnin SSTclass my self, more modded class.:cool: the sst foot works well, but still pulls some air, never did see a dozen Super Nitro's, only 6, cuzz thats how many i made. lookin at the Champs boat in the class i run, seems he gots a Super Nitro on thare, not an SSTfoot:eek::cool:

[850cc racer]

i would have to pull it apart and have a look.. which i might be able to organise..

by the looks of it in freds pic he's making a mod50 sandwich plate out of a standard one.... i can tell you it works just like the factory one:eek::cool:

so the nitro with the 1.86 ratio what are they worth?

[Fast Fred]

ya, did take a Mod50FR sandwich, and made a FT one out of it.
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[Fast Fred]

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[Popa Sam]

i would have to pull it apart and have a look.. which i might be able to organise..

by the looks of it in freds pic he's making a mod50 sandwich plate out of a standard one.... i can tell you it works just like the factory one:eek::cool:

so the nitro with the 1.86 ratio what are they worth?

Still waiting for the tooth count or pictures of the 2:1 gears.

[850cc racer]

ive been racing so havent been able to pull it apart, after this weekend coming i have about a 2 month break so ill get it stripped down and have a look in there.

850

[PIP]

Hey Race Guys, What Is The Speed Difference You Have Noticed Between The Standard 3/4 Inch Thicker Case, And The Nitro? This Is Assuming That The Correct Props Are Used On Each Since Gearing Is Different.

Also, One Guy Told Me That You Can Take An 1/8 Inch Off Of The Case By Using A Belt Sander And It Will Still Be Thick Enough For Lighter Craft.

Any Thoughts?

[Flyer]

Any chance you have any SST 60 or nitro gear cases?

[Flyer]

Any chance you know of something like this for sale?

[filthy phill]

did anyone ever come up with the tooth count on the aussie motors to get the ratio ?

I cant see why there was not different gear ratios in the larger case, it could easy of been a 2=1 ratio.

[skeg]

What other gear cases came with the 15:28 ratio? Or were they specific to the 15" 75hp ss models ?