40hp carb' on a Johnson 25

[themannsindorset]

I have seen a video of a Johnson 25hp fitted with a 30HP carb going very quickly. I have the opportunity to get a Johnson 40hp carb. Assuming it fitted, would this be a neat way of extracting that bit more power? Has anyone else done this? Would I damage the engine etc.
My engine is a model J25ELCTD 1983
Boat is a 1970 Albatross Delta "Nymph" 14 foot Speedboat All Aluminium construction.
Peter
UK

 

[F_R]

Re: 40hp carb' on a Johnson 25

I have seen a video of a Johnson 25hp fitted with a 30HP carb going very quickly. I have the opportunity to get a Johnson 40hp carb. Assuming it fitted, would this be a neat way of extracting that bit more power? Has anyone else done this? Would I damage the engine etc.
My engine is a model J25ELCTD 1983
Boat is a 1970 Albatross Delta "Nymph" 14 foot Speedboat All Aluminium construction.
Peter
UK

Don't be surprised if you actually wind up with LESS power. Especially torque at mid range. Carburetors depend on air velocity through the venturi in order to function. Making the venturi larger results in a slower air velocity.

If such a dream world exists, why not take it all the way and put the 40 carburetor on a 3hp and get a 30 MPH motor that only weighs 30 pounds?