[macojoe]

I have a 17 pitch on my Yamaha 175hp that seems to work just fine.

It kind of depends on you, what do you need?? If you want alot of speed then you will go like a 19 pitch, If you need a lot out of the hole(lot weight) power then you want like a 15 pitch. But 17 seems to be the best all around.

Kind of prop??
Most boats are factory equipped with aluminum propellers. Aluminum propellers are relatively inexpensive, easy to repair, and under normal conditions can last for many years.
And when hitting something they will offten just break the prop and not the lower unit!!

Stainless steel is more expensive, but much stronger and durable than aluminum. If you are looking for better performance than can be provided by your aluminum propeller, such as ultimate top speed or better acceleration, a stainless steel propelleris what you want.
But when you hit something you can say good by to the lower unit in most cases!

I have a Aluminum that seems to be just fine.
I have a Hustler Prop, they come in to pieces. The hub is seprate from the propeller. When you break the propeller you can replace it at 1/2 the cost as the prop is seprate. Works for me!!

I am sure there are people that can say it better then me but thats my look on the subject I hope it helps!