I have a 2004 honda 50 hp fourstroke. I have it on a lund explorer. I currently get about 30 mph out of it. I want to get more top end speed out of it. What sort of prop should I go to so I can get more speed?? Any help would be great. The prop that is on there is a stock prop. Not sure of the pitch or anything. Thanks.
The most important thing is that the engine is operating within recommended RPM ranges. You can then tweak props for performance or boat behavior.
Generally, a higher pitch prop will give you more high-end speed. The tradeoff is that you may lose some low-end performance (a.k.a. holeshot). A higher pitch prop will also reduce your engine rpms at wide open throttle. If you use a prop with too much pitch, you can reduce the rpms to a point that is below the manufacturers recommendation and shorten the life of your engine.
So, the first step is to know what the engine rpms are at wide open throttle. Do you have a tach on the boat? Once you know the rpms, you can then go into a marina and discuss the current situation and your desires.
Good luck,
Dan
You didn’t say if it was a tiller or wheel or what size Explorer. But in any case the boat is under powered no matter what model you have. (But if it’s a tiller, that may not be a bad thing. The 50 4-stroke is a very versatile motor)
30-32 is all you might get from that set up. But if you want to try and squeeze another mph out of her, here are a couple things to try.
As mentioned above try a S/S prop. Go to your dealer and get several loaner props with different pitch, size and blade combos. Each blade will have it’s plusses and minuses. A four blade prop will give you some more bow lift getting more boat out of the water.
If you have a bow mount. Add a bracket that allows you to remove the motor and lay it on the floor when running. (That alone will probably give you the most bang for the buck.)
Move all batteries to the rear. Store everyting in the rear of the boat or remove it from the boat. Only keep 1/4 to 1/2 a tank of gas on board. Remove unused seats.
All of that pain in the arse will get you maybe 1 mph.
The best and cheapest way to add speed is to add HP!
Been there > done that.
Good Luck.
Good answers, but I would like to add raising the motor if you are able can also increase the speed. You want the cavitation plate level with the hull when you are on plane.
Also, the higher number you go in prop, the LOWER you speed would get. I noticed the post above stated the opposite. Or maybe pitch and number are different. My point is if you have a 19 pitch prop, and go up to a 23, you will get hole shot like crazy, but may not max out your RPM and not reach maximum speed potential. However, if you drop down to a 17, your speed may increase as well as your RPM, but you would lose a little or a lot of hole shot. Another thing is if you go with a bigger prop, when you let off the throttle, you best be hanging on! It acts like throwing out the anchor. As mentioned, the best thing to do is get some sample props. My buddy LeRoy just gained 3-4 MPH in his 60 Merc 4 stroke 1650 Fish Hawk tiller by raising his motor 1 notch. It won’t work for everyone, but worth looking at.
Tuck
Quote:
Also, the higher number you go in prop, the LOWER you speed would get. I noticed the post above stated the opposite. Or maybe pitch and number are different. My point is if you have a 19 pitch prop, and go up to a 23, you will get hole shot like crazy, but may not max out your RPM and not reach maximum speed potential. However, if you drop down to a 17, your speed may increase as well as your RPM, but you would lose a little or a lot of hole shot.
No, no, no… he had it right. 
You got it backwards Tuck.
I got a 19 pitch prop I can jump on plane in 3 boat lenths. Top end 49mph. I have a 23 pitch, no hole shot but I can get 53 out of it.
-J.
On my old Crestliner I went from a 19 to a 21 and had the opposite effect.
Tuck is right
Quote:
Pitch
Pitch is the theoretical distance a prop moves forward in one revolution. The following propeller has a pitch that will theoretically result in 24” of forward travel in one revolution. However, in the real world, the propeller experiences “slippage” so that its actual travel per revolution is less than the stated pitch.
No so fast…..
More pitch = More speed at the same RPM’s. So, theoretically, a 23 pitch prop will alway be faster than a 19. (But as you read on that site, it does not take into consideration slippage.) Typically, with a higher pitch prop, you lose hole shot. But not always.
That’s why I recommeded trying out at least 5 different prop/blade/pitch combo’s in order to find out how the prop will best work on that particular boat. I alwasy chuckel when someone says… “This is the best prop for that boat” All depends how you have it rigged, total weight and weight distribution, motor height ect.
Make sense?
-J.
What would be the effect if the motor was set to low ? I have a Alumacraft tournament pro 170 with a 90 hp suzuki 4 stroke . Top gps speed is about 34.3 light boat. MT live wells and just me. RPMs 5500 . When I trim it to get on plane all I have to do is just raise the motor very little off of the stop at bottom. Any ideas or is this about right. Not complaining it just don’t seem right to me.
btt
i am doing this right now with my 2025 pro-v w/225 opti. i started out with a 21p lazorII and got 50 mph @5000 rpm’s. 5800 rpm’s is the goal that i am looking for. next i got a tempest plus 19p and speed went down to 49mph @5200 rpm’s i next tried a alpha 4 18p, this was a aluminum prop that i only tried to see what the rpm’s would be with a 18p, top end was only 43mph. i talked to a guy at formula propeller and he said to go to a 19p trophy. my next move will be to raise the motor up 1 more hole and see what the tempest will do. the guy at formula said that the rpm’s are more importent than top end. the top end will be what it is when you get the rpm’s right………..tomf
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