max W.O.T. @ 5200

[20vector]

hello all. my max rpm is 5000 to 5800 according to manual. my motor is getting to 5200rpm. was wondering even tho not hitting closer to 5800 am i over propping motor. my only issue with dropping pitch is that i heard if i go down pitch boat will go slower. and dont want to lose any speed but will if im harming motor. somebody told me i will lose like 8 MPH by going to a 15pitch.i got a 17pitch on her now. was wondering tho if i went to a 15pitch if i would get better gas milelage. i'm willing to lose MPH if will get alot better gas mileage but if close to same gas mileage would like to keep the speed. thanks in advance

 

[cr2k]

Re: max W.O.T. @ 5200

At 5200 you are in the range. What is your load like (people, stuff and fuel)? A 15p would probably use more gas, but I have seen stranger things.
On my sig boat I switch between a 17p and a 19p and the only diff I notice is more fuel consumption with the 17p. Yours may be on the "edge" as well.

If you can borrow or rent a 15p and see the diff for yourself. You may also get a few more RPMs out of it by trimming up a notch. But since we do not know what engine you have we would all just be guessing. Ambiguous question = ambiguous answer.

 

[Art Bernard]

Re: max W.O.T. @ 5200

I'd go with a 15 to put you more in the middle of your rpm band (give yourself some room). You would prolly loose a bit of hole shot, but gain a little top speed. Can't speak to fuel economy, that really depends on how you run and load your boat as much as prop pitch.

Art

 

[20vector]

Re: max W.O.T. @ 5200

i got a 98 200efi on a 20 foot vector hydra sports. i was told if i lower pitch i would lose speed on top end. was i told wrong. would like to get closer to 5800rpm but was scared id lose my top speed. but if i would gain top end speed will deff look into getting a 15pitch.

 

[Art Bernard]

Re: max W.O.T. @ 5200

prop pitch works like this, the lower the pitch number the more rpm's and you loose hole shot power but gain a bit of speed. The higher the pitch number the less rpm's and you loose some top speed but gain holeshot power. Allot of guys carry 2 props of differant pitch, one for pulling skiers and one for top speed.

Art

 

[1nebel0]

Re: max W.O.T. @ 5200

I don't mean to step on toes here but this is how it works.. I would step down to the 15...better hole shot, higher rpms yes, will gain back the speed and better on the motor than to be lightly loaded...People carry two props often because the smaller prop(lower pitch) is the ski prop and the larger prop is the speed prop. In this case I believe that the 15 would do better for the hole shot, and get you the higher rpm's to gain back the speed.. Yes you will use more gas but how much? Over propping a boat can cost you a piston! I have a 200h.p among many others and spin it to 6200 on my Lavey...If I only spun it to 5200 it would be 10 miles an hour slower, that is how important max rpm's are...If you got good fuel, your timing is set behind factory spec by 2 degrees you will not hurt the motor.. I had this motor on a 19ft Daytona full tunnel spinning 6500 for two years and still on same pistons, rings...that boat now has a Bridgeport that is spun 7500....Just my 02!

 

[Faztbullet]

Re: max W.O.T. @ 5200

Changing from a 17 to a 15 pitch is only 1.2 mph difference and should take rpm from 5200 to 5700