part swap

[classicjohnsons]

I have a 1974 Johnson 50 hp I am going to throw on some carbs off the 70 hp model, what other parts would i need from the 70hp to compliment this swap. Apperantly the pistons and the head is the same. any ideas???

 

[tashasdaddy]

Re: part swap

probably not going to do any good. getting the motor properly set up with the boat, and properly tuned will do more than a carb switch, the 70 has 3 carbs, the 50 only 2. the 3 cylinder is where the added hp comes from.

 

[5150abf]

Re: part swap

If the piston and the head are the same why would the carbs be different?

You would think if both engines have the same bore they would have the same carb so you are going to pretty much take off a carb and put the same one back on.

As TD said, clean your current carbs and make sure the engine is running as well as it can and that is really all you can do, there really is no "bolt on" part that will noticeably increase horse power.

Leave it like they made and it will last for years and years.

 

[Lion hunter]

Re: part swap

The carbs all have different part #'s so it's not like they just added a 3rd carb to the 70, something is different. The heads aren't the same (2cyl vs 3 cyl). And the pistons have different part #'s as well. I think to complete this swap you will need the entire 70 motor to match the carbs.

Here is the links for parts lists. Comes in handy when trying to match parts to swap between motors.
http://shop2.evinrude.com/ext/index.aspx?s1=e89bf2c8f6e136590c73d9a4716c11d8