Re: prop question
TFox<br />I think the prop you have is a good match for your boat. You are getting the right RPMs at WOT.<br />I do not know your boat size and weight but the only thing I see is the 15 inch size is usually better for big heavy boats. I think with a 13 by 19 Stainless you would gain about 3 MPH and turn about 4300 rpms if your boat is under 3000 pounds. If it heaver then then I think you have the right prop.<br /><br />My boat a 1980 Crestliner is 21 feet and a beam of 7 foot 8 inches or 92 inches. It is an aluminum boat and weighs 2800 pounds dry. Motor is a 3.0 1980 OMC stringer 400 rated then at 140HP. I have two props that I use to adjusted for difference conditions.<br /><br />Prop 1 is 13 and 3/8 by 17 3 blade stainless OMC number 389948. I use this prop in lakes and rivers where we tend to start and stop more and not travel long distances. WOT RPMs is 4600 at 35 MPH.<br /><br />Prop 2 is 13 by 19 3 blade stainless OMC number 389510. I use this prop in Ocean and San Francisco bay where we do not start and stop alot and tend to cruse as far as 30 miles one way. WOT RPMs is 4200 at 38 MPH. This prop a little slower out of the hole and gets better fuel mileage. When fishing the ocean water my boat will weigh more as we always go with full tank and lots of big weights, 10 poles or more and lots of extra gear, cameras, change of clothes more jackets, water ect. <br /><br />A trip we make over and over to a fishing grounds 26 miles offshore we will travel right around 70 miles for the day. We will only go that far out when we can run at a natural planing speed of 20 MPH. When we get back we always fill the tank.<br /><br />With the 13 by 19 prop it will take 18 Gallons to refill so get about 3.88 miles per gallon.<br /><br />With the 13 3/8 by 17 prop it will take 21 gallons to refill so get about 3.33 miles per gallon.<br /><br />I do not know if this will help you or not but at least should give you an idea of what you could expect with a smaller higher pitch prop.
I am guessing that particular OMC has a 4200 - 4600 range for WOT. Sounds like you are right there with a light load, which means you should still be there (towards the bottom) if heavily loaded. Seems like a good compromise to me. If you don't have a spare you need to buy something anyway. Learn as much as you can from all of the posts on propellers. There are lots. Also, review in the Engine FAQ section.<br /> <br />BTW, welcome.