How to choose right prop for your boat and motor

how do you know if your using the right prop for your boat?

[clintward]

I just read 20 forums and watched 5 videos on proper pitch and Rpms and finally a video that nails it on the head in 2 minutes! Awesome job!

[coachmen]

That's the best simplest most straightforward easily understood explanation

[RonTrovatoRealtor]

excellent information - finally some one knows his stuff - thanks buddy

[pospouris]

I bought a boat with an unknown history. It's a 195 sundowner and my suspicion is that the engine has been changed from a 4.3 to a 2.5 but they kept the original stern drive with a low ratio and the propeller that was 15 1/4 x 15. The engine heated and struggled to reach 4000 rpm in a calm sea. I experimented by reducing(cutting) the diameter of the prop from 15 1/4 to about 14 inches and i saw an immediate change. the engine could reach wot without getting stressed and the boat reached higher speeds of course. I now ordered a 13x15 four blade and I can't wait to try it out. sometimes you should consider diameter as a form of change. I'm told that an inch in diameter is 2 inches of pitch. not sure though, have to ask the experts.

[babtey]

Finally a simple explanation, thanks for the video.

[jimquantic]

But looking at the chart which shows which prop is correct for my boat, it shows so many different pitches, from very low to very high. Short of trying one on the water--nope, that' wrong, getting another and another until I get the specified RPM's?? Surely there must be some way to ESTIMATE the pitch, to be close out of the box, right?

[chadhunts]

Here is my problem, avoiding Blowout (Ventilation) when pulling a tube/skier and turning, WOT was fine, but I went from a factory mounted 4 blade 13 5/8x19p Spitfire and now trying a 5 blade SS 13 1/4x17P and adding a Hydrofoil hoping for more bite in the turns, lower plane speeds, and harder out of the hole. My only concern is a friends boat that is similar seemed to do best with a 14x15P 3 blade SS. I hope the 5 blade provides alot more bite like they say it does

[garygerard]

thank you - Thank You
I'm saving this video for future reference

[MrCountrycuz]

my f70 yamaha is winding out at 7000 rpm with a 15 pitch oem that was recommended to my by a dealer. top speed was 32 mph on a 18 foot carolina skiff jvx cc.
I just ordered an 18 pitch prop to see how it works out.

[buithikieu]

The video sound is pretty good, beyond my imagination

[west]

What would be the best prop for my helipropter?

[jeffdege]

Does propping for top speed always give you highest efficiency at low speeds?

I can see how a sailboat auxiliary might care more about fuel efficiency at low speeds than top speed - which is always going to be limited by hull speed anyway

[federicoferreyra]

I have a Tohatsu 40 hp 3-cylinder 2-stroke since it is a boat 460 meters deep semi-vy with 3 people plus day fishing things it does not go beyond 5200 rpm, propeller 10 1/4 .should I take a step down? could you change x a propeller 11 1/8 13? I appreciate information! thank you

[marvinnickels]

I have a 2023 190 tracker with a pro zs 115 I'm turning 6000 rpm and the motor is bolted in the top hole so it is as low as it will go! My question is it blows out without really lifting the bow! Running 43 mph GPS with tournament gear and partner! Do you have a suggestion on a different prop and setup to get more speed? TIA

[boardnamona]

So im running a 13 pitch on a honda bf50 at 6100 rpm and struggles to get out of the hole with 2 people at the back should i go to 11 pitch or 15

[jamessimmons]

I recently had my 1995 mercury mariner 200 EFI in the shop. I had Giles’fuel
pump rebuilt Reed’s put in it and water pump and seals. This boat usually carry me my passenger and all our stuff at 69 miles an hour upper River in the wind. I get it back from the shop and I have to make it get up to 61. Mile per hour I take it back to the shop. The timing was off at 17° so he said it at 21 now. I am only getting 64 miles an hour. I have lost 4 miles an hour. I’m not sure why anyone could tell me what’s going on. I would greatly appreciate it.

[Mroswaldo]

We have a vmax series 2 250hp. We have a 4 blade 24 pitch. At wot it reach around 5400rpm. 61mph.
Engine specs states 250 at 5500rpm. So 5500rpm is the max rpm? To see if my boat is overprop. Just got a 3 blade 24 pitch.

Didnt stay at WOT throttle for long. It just reach 61/5400rpm & let go.

[jorgeramos]

I have a 3008 cartepillar Marine engine diesel 320 hp not sure what propeller to get ??

[knifesharpeningnorway]

I have a 2018 mercury 100 hp command thrust with today a black max aluminium 17p that slips on the water under hard accelration or trimming out on the outboard. I bought a slightly used mercury vengeance 19p can i use the samme flo torq ii hub kit i use on the black max on this vengeance prop?

[PontoonPilot]

Heres my conundrum... I had a 15x17 mercury prop on my boat when i bought it used with only 50 hours on tge entire boat and yamaha 150 outboard 4 stroke motor. (2011 Southbay Tri-toon 24'). I was getting easily 5800-5900rpm and 40mph (give or take a coiple mph depending on water conditions and fouling on pontoons causing drag..) that prop was knocked up a bit.. so I bought a new one.. same size and pitch 15x17. Yet cant get over 4900 to 5000 rpm trimmed out! And maybe 32 mph.. (recently 28mph due to dome algea growth on pontoons) but even clean.. wasnt getting more than 5000rpm and 32mph