1987 Johnson 20 hp to 30 hp

[wbeaton]

I have a 1987 Johnson 20 hp and out of curiosity I decided to see what the difference was between it and the 25/30 hp of the same year since they all share a common block. After pouring over the part numbers for all three motors it would appear that the only difference between the 20 hp and 25 hp is the intake manifold and the 20/25 hp and the 30 hp is the intake and carb. Has anyone here looked into this? It might not be worth the trouble for 5 hp, but for an extra 10 hp I’d consider the swap.

 

[jimmbo]

Re: 1987 Johnson 20 hp to 30 hp

They share the same displacement. What parts were you comparing?

 

[wbeaton]

Re: 1987 Johnson 20 hp to 30 hp

I looked at pretty much everything in my parts manual for the 20/25 hp and the 30 hp parts manual on the BRP website. There didn't seem to be many differences. Only the intake and carbs were significant - that I could see.

 

[James Tobias]

Re: 1987 Johnson 20 hp to 30 hp

I looked at pretty much everything in my parts manual for the 20/25 hp and the 30 hp parts manual on the BRP website. There didn't seem to be many differences. Only the intake and carbs were significant - that I could see.

just found this site today.
would be interested in a pic of your 20hp johnson,if you can send one.have opp to buy an old one and would like to compare. thanks
jt4345@comcast.net

 

[wbeaton]

Re: 1987 Johnson 20 hp to 30 hp

Hi James,

Sorry I haven't replied sooner. I thought this was a dead topic. I've sent pics. Hope its not too late.