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Reply With QuoteThat's a big boat for a 40. What's the boat rated for, 90hp? Your rpm is in the correct range, indicating that you are running the right pitch prop.
Slabmaster
Boat speed
I have a 17.5 Alumacraft Maverick with a 97 40hp force. Prop pitch is 11 running 5500 to 5700 rpm. With me and my son 8yrs old 2 tackle boxes and rods, empty livewell and full fuel tank. I’m running 21 to 23 mph. Is that about right? I thought it should be in upper 20’s range.
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Crappie Wall Hanger II
That's a big boat for a 40. What's the boat rated for, 90hp? Your rpm is in the correct range, indicating that you are running the right pitch prop.
I'd rather be fishing.
Slabmaster
Boat speed
I was wrong on the length. Spec’s list it at 16.33 and max is 70hp. Boat weight is 535lbs.
Anything that I can do to get a little more out of it.
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I have same boat with 40 mariner/Yamaha 2 cylinder with 11 in stainless prop. It is on a add on trim and tilt unit which set it back and up some. It would run in upper 20's to 30 depending on water and load. I would expect a little more out of yours depending on prop type and set up. Are you using GPS or speedo?
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Charlie Weaver USN/ENC 1965-1979
Slabmaster
GPS app I downloaded to my phone. Would raising the motor up one hole make a difference. Prop is a 3 blade Michigan wheel aluminum.Originally Posted by Cray
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Don't think I would with aluminum prop. She looks to be about right where it is setting. With stainless you can run higher because of the added bite they have. Afraid you would get to much air and cavitate the prop or spin it out. Do you have trim and tilt on this motor?GPS app I downloaded to my phone. Would raising the motor up one hole make a difference. Prop is a 3 blade Michigan wheel aluminum.
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Proud Member of Team Geezer
Charlie Weaver USN/ENC 1965-1979
Slabmaster
It has trim for sure. I noticed the smaller holes that looks like I can tilt I haven't to closely at it though.
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Have you tried different trim settings to see how that affected your speed?
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Charlie Weaver USN/ENC 1965-1979
Slabmaster
Nope because I just noticed them today. Should I tilt it out more?
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My original question about trim should have read, do you have hydraulic trim and tilt that works off a button in throttle lever or some other button? If not here is what you do, looks like in first picture there is a nut on a bolt through bottom hole. It definatley is trimmed in to far if that's where it sits all the time. Tilt motor up, move that bolt up one notch or hole, then put in water and give it a try. As you go up you will see it take a little longer to get up on plane. You want to move it up until it starts to blow out when it try's to tip over on plane. Need to have a calm day and not much ramp traffic so you can play with it until you reach a happy medium. I hope all this is helping and not frustrating you.
