vintage Johnson interchangeability

Joined
Apr 20, 2014
Messages
2
Hi there, I'm new to the forum and I wanted to ask if anyone knows anything about the interchangeability between a 1955 RDE 17 25 hp and a 1957 RDE 19 35 hp. The 19 has a good powerhead, but the lower end seems seized (shifter won't budge). The 17 powerhead is hopelessly seized, but the lower end seems ok. I thought I might change the seals and gaskets on the 17 lower end, and stick the 19 powerhead on it. They seem visually identical. I'm trying to put a vintage engine together for a 1959 Whitehouse Sailfish. I would appreciate your advice. Thanks!
 

HighTrim

Supreme Mariner
Joined
Jun 21, 2007
Messages
10,486
Re: vintage Johnson interchangeability

Yes you can swap them, but curious about the RDE19 gearcase.

Have you spun the prop while trying to shift?

Is the actual drive stuck, or just the shifter? May just be a simple fix. If you were going to open up the '55 gearcase anyways, why not open up the '57
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: vintage Johnson interchangeability

The 35hp has a stronger gearcase to handle the extra power. Different pinion gear & bearings. I'd stay with that one unless it is hopeless.
 
Joined
Apr 20, 2014
Messages
2
Re: vintage Johnson interchangeability

I haven't messed with the linkage yet, so it's possible that could be the problem. I'm thinking worst case scenario. Another reason I was considering the swap was that the 17 is a strictly fresh water engine, and the 19 saw lots of salt use. I assume it's in better shape. As a matter of course (and not to end up stranded in the bay!), I wanted to replace all seals and gaskets in the 17 lower end anyway. I'm going to powder coat the motor piece by piece, and the seals and innards all have to come out, before I send the lower housing to the paint shop. Any special precautions to take? F R, I noticed you're from the Florida Gulf Coast. I'm in Pensacola.
 

1946Zephyr

Vice Admiral
Joined
Oct 21, 2008
Messages
5,556
Re: vintage Johnson interchangeability

If the gearcase on the 17 is in nice shape, you should be able to transfer all the innards from the 19, over to it, that way, you will have the heftier gears and pinion.
 
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