1968 20hp johnson

[Duckhunter2009]

I have a 1968 20hp johnson motor. Model number fd-22m. I'm new to boats and wondering if there's a way to get anymore power out of this motor.

 

[racerone]

Re: 1968 20hp johnson

It is a 22 cubic inch motor.----Later models in the early 1970's were produced as 25 HP models.---------I am not going to explain the subtle differences here.------A complete donor powerhead would swap right onto your midsection.

 

[F_R]

Re: 1968 20hp johnson

"Subtle differences" include different pistons, different rings, different cylinder head, different carburetor, a balanced crankshaft for higher RPM, and different exhaust tuning. Changing any one or two items without the whole shebang will likely result in less power and possibly even severe engine damage.

Story from here is leave it alone. Besides, 5hp will only amount to a couple of miles per hour on most boats, not even noticeable in the seat of the pants.

BTW, there is always somebody that has to try it anyway. Like me. I did the whole shebang, and the result was it wasn't worth it.

 

[kfa4303]

Re: 1968 20hp johnson

HI Duck. Welcome to iboats. No way to really get any more power out of these old girl, but when properly tuned, they're pretty powerful. I have a '66 20hp myself and it's pretty plucky. Here are some handy links to help you give it a tune up from top to bottom. You can get any routine parts you may need right here at iboats.

Maintaining Johnson E & FD Serie

1968 Johnson FD-22M 20 hp Outboard Motor Parts

 

[boobie]

Re: 1968 20hp johnson

"Leave a sleeping dog lie" as long as it's running good.