Switching power heads

[Nutron]

I am trying to find out if I can switch my power head. Here is the engine model and hp. I currently have a 1984 Johnson 90hp outboard, model J90MLCRD. I have a bad cylinder on this motor and found a good deal on a power head I want to swap out with, here is the power head information, 90HP 1987 crossflow V4 J90TLCUR. I want to swap the 1984 that has a bad cylinder with the 87, just wondering if it will fit on my outboard, thanks for your help.

Nutron

 

[Daviet]

Re: Switching power heads

You might try looking up some of the parts, base gasket and block, in the parts break downs and see if they are the same.
Look in the "Top Secret File", there is a list of salvage yards there, maybe they might have a conversion chart or something that will help you out.

 

[ryguy1101]

Re: Switching power heads

If they're both crossflows, the blocks will swap. Crossflow blocks from the 70's, 80's, and first half of the 90's are relatively interchangeable. The question is will the electrical and all of the other peripheral stuff? Got photos of each?

 

[guy74]

Re: Switching power heads

I think you will be fine with that switch, the electronics and such should also interchange as well. 1984 was the first year of a change, and 87 was the last year of that "Generation". I swapped a 1987 powerhead onto my 1989 but had to make a mounting plate to mount the single powerpack, as the 87 was still a twin powerpack setup. Goodluck!