Evinrude/Johnson 50-60HP power head interchangability?

reelfishin · #1 November 2nd, 2009, 03:51 AM

I just picked up a 1981 50hp Evinrude which runs like a top and has a two week old power head. The problem is the lower unit is smashed, to badly damaged to repair, and the mid section has many broken bolts.

Now I have a 1984 Johnson 60HP with a blown up power head, fresh rebuilt lower, new water pump, and perfect mid section. Both are 20" shaft motors. Can I use the power head from the '81 50hp on the 60hp?
Even if the result is a 50hp I figure it don't much matter so lone as it works.

tashasdaddy · #2 November 2nd, 2009, 06:14 AM

this should help some. http://forums.iboats.com/showthread.php?t=359907

reelfishin · #3 November 2nd, 2009, 02:25 PM

Thanks, That clears up a few questions but how about power head interchangeability?
Will the power head itself from say a 1989 work on a 1981?
If not a direct swap can it be made to work?

(IE: Will the crank and bolt patterns mate up?)

How many lower units were used over the years on the 50-60hp motors?
I have a 55hp which looks to use a 70hp mid and lower.
I have two 1985 motors both have a larger hub diameter than does the 1987, or the 1989 for that matter? Were there two or more lower units for these motors?
Do the small and large diameter lower units interchange?

tashasdaddy · #4 November 3rd, 2009, 06:39 AM

the list is a direct interchange, with the power head. as far as the bolt pattern to the mid section, i am not sure. but assume it would bolt up. OMC, designed things to work on different motors, it cut production cost.

Faztbullet · #5 November 3rd, 2009, 09:41 AM

The 1981 & 1984 will interchange with each other as long as both are 2 cylinder engines. The 1989 will not work as driveshaft splines are different, the only way to get the 1989 to work on the 1981 is to change crankshaft.

reelfishin · #6 November 4th, 2009, 03:52 AM

Quote:

Originally Posted by Faztbullet

The 1981 & 1984 will interchange with each other as long as both are 2 cylinder engines. The 1989 will not work as driveshaft splines are different, the only way to get the 1989 to work on the 1981 is to change crankshaft.

This is what I was after, Thanks.
I'll pawn off the 1989 then and stick with all one engine family. I'm not a big fan of the newer bracket and tilt piston nor the smaller lower units anyhow.

Besides, it wouldn't make sense to tear apart a good power head to change a crank just to make it work. The way I see it, the 1989 needs a tilt unit, which exceeds it's value right there, the lower unit is of no use to me on any of my other motors, and it's also a short shaft, so it's out of here.