Gear case Compatibility, 1974 Evinrude 115hp with 1975 Johnson 135hp?

[JTKelleyiii]

Would the '74 115hp Evinrude gear case work on a '75 135hp Johnson? From what I can see it should work but would appreciate input from you pro's. Thanks

 

[emdsapmgr]

You've got some old part number questions. The old OMC data base sheds a clue. It does not show any supercession between the years of these units.
But there is a hint that this will work on the factory part description of the 75 135 lower unit: 387580 gearcase 73-76. They should interchange.

 

[JTKelleyiii]

Thanks. I think it should work.

 

[JTKelleyiii]

Is there any difference in the gearing betwwen a 115 and a 135?

 

[racerone]

The 135 had a different gear ratio compared to 85 /115 models for some years.----Only checked my 1973 brochure to confirm this.

 

[Bob_VT]

No the gears are the same ratio ................

 

[racerone]

The factory brochure showed a different gear ratio !!!

 

[Faztbullet]

The 135 has a different ratio 13:25 or 1:65 where 115 is 2:1

 

[emdsapmgr]

My factory 1976 135 service manual confirms the gear ratio at 13:25.

 

[JTKelleyiii]

So, is this a bad idea?

 

[emdsapmgr]

Don't give up on swapping the gearcases. The 115 case ratio is a slightly lower ratio. On the 135, you'd have to run that 115 gearcase with a higher pitch prop than the one you ran on the normal 135 case. Other than that, I doubt you'd notice the difference.