best pitch prop for boat

[geangee]

hello everyone . I have a 1973 v-145 fireflite with a 1982 50hp mercury outboard and would like to know what the best pitch prop is for this boat .i got it 6 months ago and love it . if anyone can help that would be great . im living in new zealand and no one really knows as its the aqua-lift 2 hull and theres not many here .

[Rich_V174SS]

The best way to determine a correct prop is to compare it to the performance of what you're already using along with rpm reading at full throttle. You have to match the prop with the engine/boat combination so what might work for someone else may not necessarily be the best setup for you. What we would need to know is what size prop you have on it now, what material it's made of (assuming aluminum) and what you're getting for full throttle rpm so you should have a working and accurate tachometer. You want to try to achieve around 5500 rpm wide open, choose less pitch for more rpm, more pitch for less rpm. After determining your optimum pitch then perhaps a switch from an aluminum to stainless prop will give you better performance on top.

[Fuzzbutt]

I'd have to also agree with Rich on this. A book/chart might get you in a ball park place to start if you don't currently have a decent prop (lost/damaged) but trial and error is about the only way to really know. You'll need a accurate tachometer and time.

FWIW I purchased my motor off a different boat and had to start from scratch on my prop choices. I had 5 different props at one point. Narrowed it down to my favorite 3 now.