I need help for prop size

Shubbar

Shubbar

Member
Hello every one i have wellcraft V20 step lift and Johnson 175 Ocean Runner 1995 Counter-rotating and i have 3 size prop 17 19 and 21
what is the best prop i can used to my engine i need speed and good for my boat engine
thank you
 
If everything is as it should be with the boat/motor setup the 17 should turn up a little too high and the 21 too low.
Try the 19 and see how it performs.

Most guys with a 150 horse do real good with a 17 pitch, some with a 15 and a couple with a 19.
 
What do you mean by "good for your boat"? If you mean what is the best prop for your engine, then the answer is whichever prop lets your engine turn at 5500 RPMs with the throttle wide open is the best for your boat.

It's hard to guess accurately what prop that would be since there are so many things that can effect your final speed. Amount of fuel, number of persons on the boat, food, bait, tackle, anything that adds weight will effect your top end speed. Additionally, if your hull is smooth or rough will effect it also, plus how you have your engine trimmed... All these things can and will have an effect.

As both Spareparts and Tsubaki have already said, try the 19 Pitch prop first. If your engine RPM is right around 5500 rpm then it probably is the best one for your boat. Only you can make that determination after trying it though.
 
Most run a 17. If you don't carry any additional weight and want to have more top end speed run a 19, but it won't plane off as quickly.
 
Shubbar said:
Hello every one i have wellcraft V20 step lift and Johnson 175 Ocean Runner 1995 Counter-rotating and i have 3 size prop 17 19 and 21
what is the best prop i can used to my engine i need speed and good for my boat engine
thank you
Click to expand...

Those were the same 3 choices available to me when setting up my 1st 200HP on my present '84 V20...and you are right between my present and past motors re HP!!......BOTH 150s I had performed their best w/17s...the Honda spun up to 6 grand w/a 17...perfect for THAT motor...my 200, I'm still not sure about, but indications are the 19 will be the pick...haven't actually run the 17, but will before final decision...I'm thinking the 19 for yours since the 175's redline is 55...you want to test that under best possible conditions...flat water, no wind, light load(not the trip for all your buddies and their beer...lol!!), low fuel, top down and motor trimmed out as far as possible and still getting FULL BITE...if under that condition, she redlines @ WOT, then THAT'S yer prop...let us know how it comes out...
 
reelapeelin said:
...my 200, I'm still not sure about, but indications are the 19 will be the pick.....
Click to expand...

Reel, I run a 19Pss on both my Cruisers 200 Merc and my Wellcraft 200 Johnnyrude. Seems like the proper prop for a 200 engine.. I know a lot of different things make the final determination, but I'm willing to bet that you'll settle on the 19 (or maybe a 21 if you go Alum) :head:
 
Shubbar said:
hi now i don't know what prop i used i need speed and low RPM
Click to expand...

NO, you need speed and whatever the RPM is that your engine maker says you need. The higher the RPM, the higher the speed. Your engine maker will give you a figure for a point where your engine is most comfortable running. That figure is expressed as WOT or Wide Open Throttle. Typically, that will be around 5500 rpms for a 2 stroke engine. That is the speed that your engine is most comfortable at.
 
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