X-115 GT-115 gear case guts

[Mark75H]

Dave knows its a left, he's joking that putting the shifter arm on backwards changes the rotation. He got you.

[Powerabout]

yep
got me!

[brichter]

Here is a cutaway view of the assembly and a picture of a complete GT115 motor.

[Dave S.]

I am at a mess when it comes to putting that shifter back in. Was hard comming out any one know any tricks.???? Thanks Dave S.

[wolfgang]

Here is a cutaway view of the assembly and a picture of a complete GT115 motor.

The GT115 and the 55hp SE engine made their appearance with exactly that lu in `67/`68. The fact that OMC served the teams running the two different motors with props out of the same box, leads to the assumption that the lus were fitted with different ratios. However, our `69 SE motor really got going when fitted with ss aftermarket props (made in Sweden).

[Mark75H]

Inspection sheets show the same 14:23 ratio for both motors

[wolfgang]

Here is a cutaway view of the assembly and a picture of a complete GT115 motor.

PS: in retrospect still amazing that with underside of propshaft in line with underside of keel on both deep Vee boats (Grupstra and Dalla Pieta`), the motor still could pick up sufficient cooling water through the gills above the torpedo. We never experienced a cooling system related failure, and in 2 1/2 years only had one upper crankcase seal and one rectifier failure.

[wolfgang]

Inspection sheets show the same 14:23 ratio for both motors

I am well aware of that, but that does not explain my conundrum, The Swedish aftermarket props turned out some 3/4" smaller in diameter than the works props. They spooled up better and seemed to track better. Only the experimental 4-blader might have required more development time, with potentially a reduction in diameter.

[Mark75H]

I don't understand the puzzle ... assumed different ratios, but were not ... smaller props worked better ... agrees with having the same ratio

I see agreement, not puzzlement