85 HP Johnson parts interchangeability?

[N3UP]

I have an 85ETLR77S that has side tilt that is junk.

I just picked up an 85ESL74B for parts to get the manual reverse lock setup.
As far as I know the 74 motor has a powerhead issue (it was overheated) and other than the power tilt the 77 is a good motor.

Can the the mount be easily swapped from the 74 to the 77, or do I have to swap the powerhead?

I don't mind making a "Frankenmotor" out of the parts I have, but being new to Johnsons, I'm still learning about what can be swapped.

Unless I can easily transplant the reverse lock, I was thinking about putting the 77 powerhead and lower unit on the 74 midsection.

The 77 lower unit has a better skeg, and the 74 lower looks like it's been hit more than a few times.

One concern is the cowl in the 74 has "Powershift II" decals. What is Powershift II?

Thoughts, comments.....
go easy on the noob.....

 

[tashasdaddy]

Re: 85 HP Johnson parts interchangeability?

the 1974, has a hydro mecanical shift lower unit. the 1977 has a Mechanical Shift lower unit. the drive shaft splines, and the shift mecanism are different.

the trim & tilt has been added to the 1974, as they did not come with it. could possibly work with the 1977.

 

[N3UP]

Re: 85 HP Johnson parts interchangeability?

The 74 does not have tilt/trim. The 77 does, which I want to remove.

Are the midsections the same?
Can I use the 77 powerhead and lower with the 74 mid as long as I use the 77 drive shaft?

 

[N3UP]

Re: 85 HP Johnson parts interchangeability?

How about the powerheads? Could the 74 be rebuilt as a spare? Assuming it's not too damaged of course?

 

[ezmobee]

Re: 85 HP Johnson parts interchangeability?

The TnT should work. (those pre-'78 TnT units go for around $400 on ebay!)

 

[ezeke]

Re: 85 HP Johnson parts interchangeability?

Most of the 1977 85HP motors had the same hydraulically assisted mechanical gearcase as the 1974 V4 motors. You can distinguish them by the skeg, which is perpendicular to the propeller shaft, not angled back.

The extra long shaft models had the newer gearcase and midsection and vitually nothing transfers from 1974 to them.

There were no stock PT&T units in 1974, they came out in 1975 and were sold as add on kits for the 1973, 1974 and 1975 V4 motors and for conversion of manual tilt 1976 and 1977 models. If you have the 85ETLR77S model, just about everything on the 1974 model will transfer.

The ignition systems were improved in 1976 when the black ignition coils were added, so the ignition system is considered to be better on the 1977 than 1974.

 

[ezeke]

Re: 85 HP Johnson parts interchangeability?

If you need to replace the PT&T pump, here is a complete one that will work: http://cgi.ebay.com/ebaymotors/ws/e...925417&viewitem=&sspagename=ADME:B:SS:US:1123

 

[N3UP]

Re: 85 HP Johnson parts interchangeability?

Ezeke,
Thanks for the info.
I'll try to post some pictures maybe over the weekend, but I think I understand what you describe about the skeg on the lower unit.

As far as the TnT goes, the 77 motor had what I was told is side trim.
The motor seems to be dead, and the bracket that the cylinders attach to on the bottom looks like it was broken at some point, and was poorly repaired.
It's pretty crappy looking, and besides, I don't have any of the relays, wiring harnesses or controls to make it work.

This is a pretty low budget project so far and TnT is a potential maintenance headache that I really don't want to deal with going forward.
Manual tilt is just fine for me....

We paid $300 for the 77 motor and we were told that it should only need a fuel pump. Compression was claimed to be 140 on all four, but we have not confirmed that yet. We also got 2 control boxes, but one is pretty much junk, the other appears repairable.

I picked up the 74 motor for $100 and got a nice Evinrude control box (looks identical, are they?) and a spare prop as well.

The best prop is on the 74, but I figure with 3 props (all look refurbishable) I should be able to barter my way to a decent one with not too many bucks added.

I already have a new fuel pump on hand, so I'm hoping to get the motor stand built sometime next week and get the 77 on the stand, checked out and running before it gets too cold. Fuel lines, plugs and maybe a carb rebuild is hopefully all it will need.

One other question.
The Hydraulic assisted lower units use something other than the usual gear lube, right?

 

[ezmobee]

Re: 85 HP Johnson parts interchangeability?

I think your "side trim" might be the tilt only option. They had optional power trim and tilt and also just power tilt. I believe it just had one ram and not enough power to hold the motor in position against the force of propulsion, thus, just power tilt.

The hydro lowers did not require special lube. Just the elec ones did. (I had a '73)

 

[ezeke]

Re: 85 HP Johnson parts interchangeability?

The Tilt Only units were available long before the PT&T units that came out in 1975. They only had one cylinder where the PT&T units have two, one on each side. See the thumbnail for the components of the PT&T unit.

1977 Johnson models with a T in the model number like yours had the complete PT&T factory installed.

The recommended gear oil was OMC/BRP Hi Vis, which is 75-90, but any good quality marine outboard gear oil in that weight range will work. Because the shift is hydraulically assisted, you need to have the gearcase filled for the unit to work correctly.

 

[N3UP]

Re: 85 HP Johnson parts interchangeability?

I have the 73-77 Hyd assist gear cases on both motors.
Thanks for the pics.
Now to find time to get to work on it.....