Re: Need new Prop
With that little bit of data and not knowing what kind of boat you have we can't help you much. I'm guessing that you have a 17 - 18 foot boat which should probably have a 19P prop. But it may be you already have the best setup and 50 MPH is simply not achievable. So -- you need to do the following: 1) make sure your engine is tuned properly, the hull is clean and you are not lugging a boat load of water soaked foam, 2) engine mounting height is optimal, 3) make some test runs with average load and note WOT RPM and maximum speed (preferably via GPS). RPM is important as you want the engine to run at it's maximum recommended WOT rpm with an average load. If it doesn't reach that RPM, you need less pitch. If it's higher than recommended (over-reving) you need more pitch. Speed will end up being whatever that prop gives you. Do a search for prop calculators. Entering the data from your test runs will give you an idea where you are with your setup and which way you need to go with prop selection. Remember though, although a prop calculator will indicate you can reach 50 MPH with a prop of given pitch, your engine may not have enough power to twist that prop. There are limits.
