Need better Holeshot.

[Mazda3GT]

I have an 18" larson bowrider with a 1999 135hh V6 Mercury outboard. Currently Im running a 14" by 23P prop which seems to be a good top end prop. From experience from past boats If you have a good top end prop, just drop it 2 pitches and it seems to do fine for holeshot. I found a brand new prop for $80 someone is selling privately, its a 14 1/4" by 21P. Would this be close to dropping 2 pitches in a 14" diameter. I have some experience with changing pitches of props, but no experience with different diameters. Anybody have any advice?

Thanks,
Steve.

 

[steelespike]

Re: Need better Holeshot.

Without your present rpm and speed its difficult to make specific recommendation.
Diameter is not usually considered; as it is a product of the design.If intended for your application it should fit.If both props are the same material
a 21" should raise your rpm "about 400" and improve hole shot.
The motor needs to operate within its rated rpm.If it tends to over rev just throttle back a little.

 

[boat1010]

Re: Need better Holeshot.

I guess I am surprised that it will push a 23p. But you are right a 21p will give you a better hole shot. Just watch the WOT RPM.

 

[Mazda3GT]

Re: Need better Holeshot.

I was surpirsed it could push a 23P as well, the larson must be a light boat. But the engine has alot of power, I heard its the same block as the 200HP, just some tunning differences, exhaust and injectors, minor differences. Anyhow 20 i know dropping 2 pitches will increase about 400 rpm at WOT, but since the prop is a 1/4" difference now what should I expect?

 

[Mazda3GT]

Re: Need better Holeshot.

The boat tops out presently at 51MPH fully trimmed two people aboard. So I am happy with this prop for speeding around in, But I want a prop speciffically for watersprots, I may never go full out on this prop. Right now I believe it tops out at 5400 rpm, if my memory serves me correct (its been a long winter). I have the book for my motor and will not cross the recomended rpm range. What I wanted to know is will the diameter of a 1/4" effect the rpm's? or by dropping two pitches and increasing a 1/4" will still eqaul a difference of 400 RPM at WOT.

 

[steelespike]

Re: Need better Holeshot.

No prop change is 100% predictable.Don't forget the 200 rpm per inch is an approximation. Just changing brands creates additional variables.I don't believe 1/4" will even be noticeable.Yes it could reduce rpm.
If your going from Al.to Al.You might check out the Turning Point Hustler or
Rascal.These do improve overall performance.Not an unbelieveable amount
and at 51 mph if you manage any increases other than hole shot be very [happy.

 

[180shabah]

Re: Need better Holeshot.

The rascal is for small OB's.

The Hustler and Legacy are for larger OB's and I/O's. They are also vented, which helps with holeshot, so you may be able to keep your 23" pitch and pull tuber, skiers etc.

 

[Randybeall]

Re: Need better Holeshot.

To get back to your specific question. 1/4 inch of diameter is totaly ignorable, if the prop is specified for your engine. The diameter of a prop is actually a range that the prop builders work with. They design a pitch, with or without cupping, rake and all that other stuff and come up with a design. It may be 13 3/4 to 14 1/4 or even more. They check it with the engines they specify it for to make sure it will properly clear the anti vent plate or what ever limits size on the engine. That much change in diameter makes almost no measureable change in engine performance, the design makes the difference. If you are buying a used prop go to the prop manufacturers web site and check the prop number to see if it is specified for your engine, that is all there is to it. Happy Boating.

 

[hwsiii]

Re: Need better Holeshot.

Mazda, if you are staying with the same model of prop you will gain about 100 to 150 RPM's in the change over. But if you are changing to a different model prop all bets are off, there are just too many variables.
Change from 23" to 21" gain about 350 RPM's
Change form 14" to 14.25" lose about 200 RPMs
Net Gain about 150 RPM's

Hope this helps


H

 

[180shabah]

Re: Need better Holeshot.

I would call TurningPoint customer service and give them your current setup and performance numbers and get a recomendation from them.

They have let people exhange props that were ordered with the "wrong" pitch, but it might be quicker to get a hub(if you don't already have one) and botht the 21" and 23". Test with both and return one of them. Either way talk to them first.

 

[Mazda3GT]

Re: Need better Holeshot.

Thanks for all the help. I think Im just going to buy brand new and try out a few props. The world of props is so vast, and their importance is huge. Im very happy with my 23P prop, its a great all round prop, even pulls a 180lb guy out on a slalom ski no problem, but when I am skiing I love being popped out of the water at break-neck speeds, I love holeshot for watersports. So Im looking stirctly for a watersports prop, not a cruising prop, this prop will have only one purpose. I was even considering a 4 or 5 blade prop, but I hear these are more for big and heavy boats with lots of power/torque. I wouldnt mind trying one out though.

Thanks again,
Steve

 

[180shabah]

Re: Need better Holeshot.

I was even considering a 4 or 5 blade prop, but I hear these are more for big and heavy boats with lots of power/torque.

Not true. While some props are suited to heavy boats, some will be just fine for your intended usage. In fact Merc's "High-Five" was designed specificaly for watersports and usually swaps for the exact same pitch.

 

[Utahboatnut]

Re: Need better Holeshot.

I agree with the above on the HI-5, I have one on my boat and for watersports nothing can touch them. I do lose some off the top end and have to really monitor the tach if I'm cruising with it but for out of the hole performance it is the best prop I have had yet. I noticed when I had my outboard that the vented props do make a big difference on the hole shot, but a 23 seems huge for that motor I am surprised it will pull a slalom skier out of the well.

 

[Mazda3GT]

Re: Need better Holeshot.

I am surprised as well that the boat does pretty well turning a 14 X 23P prop, the motor seems to have alot of torque, I am really impressed with this motor, its a true workhorse. My only complaint with the motor is that it dies once in a while when it idles for extended periods of time. I heard this is a common problem for this motor with no real cure. I will look into those high five props, but damn they are not cheap, I have to try it before I buy it, If im impressed I got no problem spending the coin, but if it isnt much different then a lesser pitch 3 blade, then the 3 blade will be the way to go. Again thanks for everyones input, all this boat talk is getting me excited for boating season!

Thanks,
Steve

 

[sleeper]

Re: Need better Holeshot.

I would try a turning point hustler aluminum in 21 pitch. It is a lower pitch and is vented so it will improve hole shot, but it is also cupped which will lower the rpm increase from going to a lower pitch. I was thoroughly impressed with it. I went from a 23 pitch near the middle/top of the recommended rpm range, to the hustler in a 21 pitch and now it runs at the very top of the range and the hole shop is night and day better. Plus its a cheap prop, don't waste money on a high dollar one until you try that one.