40 hp Yamaha prop on a pontoon

[newbie4life]

So, I bought this pontoon from my uncle last week. He said his prop was beat up pretty good, and he found one on a thrift sale. :facepalm:

Took it out for the first time last night after spending a week putting on a new floor, new rails and had a friend make new couches for it. Spiffy.

New information: Prop size is a 10 3/8" x 13. As I look on the iboats prop finder, the prop is just dead wrong for this outboard. It should be almost 2" bigger in diameter. I really don't know if I can even use this prop as a benchmark, can I? I'm used to using what I have, and then going up or down in pitch according to the performance of the boat... but being this one is completely wrong, can I even do that?

The engine felt sluggish, a friend pulled the carbs apart (again) and found more crap in the carbs (again). Put it back together, and it's running fine again -- want to take it back out on the water this weekend -- but would like a prop that would be more 'fitting' for this engine.

Thanks for any help!

 

[steelespike]

Re: 40 hp Yamaha prop on a pontoon

You should put a filter in to catch the crud.
While you told is a lot we need a lot more.Please read the stickys at the top of the page and get us as much info as possible.
The 40 uses 10 3/8 props in the higher pitches Your pontoon likely will use something like a 9" pitch which is a larger diameter.
Usually as pitch goes down diameter goes up.