Swapping out engines

[TAC_Double]

So, It's time to take the 1975 40hp off my pontoon and put the new 1975 85hp on. I have been told that I need to take it to the shop hand have it done because it is almost a science to get it installed correctly.

Is this true? It seems to me that as long as it is centered on the transom, it should be good to go.

Whats the story?

Any advice or tips?

Thanks!

 

[tashasdaddy]

Re: Swapping out engines

are the shafts the same length? if so perfectly centered should be good. you may have to play with the tilt/trim and may height to get optimum out of the engine. remember to prop it correctly for the toon.

 

[TAC_Double]

Re: Swapping out engines

The current engine has a 25" shaft, the 85hp is a 20". From what I have read the 20" is the correct size for my boat.


Thanks for the advice.

 

[R.Johnson]

Re: Swapping out engines

Keep in mind! That engine has to run up in it's RPM band, if run on a pontoon, 5500 RPM at WOT. If you are just going to idle around, you don't want that large of an engine. But if you do, and run full throttle, than you must prop accoardingly. Think of high gear all of the time

 

[TAC_Double]

Re: Swapping out engines

Well, The current motor... 40hp just putts around takes forever to cross the lake. and I do mean forever when I have a load. I want to be able to get around a little quicker, and the kids want to be pulled around on some tubes. So it will be running at WOT.

How do I know what prop to run? I am a little confused on how to choose the right prop.