Prop question

[BWT]

Hello, I have a question I'm for you guys.. I purchased a 2004 25' Voyager TriToon with a 5.7 Mercury and a Alfa drive last weekend... The prop that's on it cavitates once you get on plane, it looks like it was ran through a rock pile and I can't make out any of the numbers that are on it. Does anyone here know what prop would come on this boat from the factory? I'm thinking a 4 blade 20 but would like to be sure before I go buy one..

Thanks

[RcgTexas]

Welcome BWT!

A prop shop could tell you the pitch for sure and probably the diameter. I couldn't even if it was sitting here if it isn't stamped on it.

I'm guessing a dealer of that engine and drive could say what is usually put on it. wish I could be of more assistance.

[Bryden24shp]

Some props are stamped on the back of the exhaust port. Take the prop off and look around the area where you removed the castle nut and washer, it may have stampings in that area. I'm thinking a 4 bladed 20 pitch may be a bit steep on that application. I would like to see you run about a 15 1/4 diameter 18 pitch Mirage Plus once. They are cheap used. Ebay...

[BWT]

Thank you guys for the responses, I will check out the prop closer to see if I can find something on it.. I'm close to Havasu AZ and think there may be some shops up there that may let me do a trial and air tell I fint the correct one.

[Seon]

Speaking of props on a Toon... in order to pick the correct pitch would it be the same as any boat and that is running the Toon at WOT to attain 5500-6000 rpm?

[Bryden24shp]

Yes, you want to try to achieve the manufacturers maximum RPM recommendation. Too high you will hit the rev limiter (cylinder cut out) too low will overload the powerhead. A few hundred low won't hurt anything. Prop it with what you think will be an average weight load on board.