Prop for my V
 

ok, I've read and read about the proper porp size for my V. I need a little help because it is all so confusing. Here are the details, best I know. Any help would be appreciated.

Standard V20 Center Console
Evinrude 150
WOT = ? unknown (Ferm or tsubuki might be able to help on this)

I don't know what else I need to supply to help.

I'm running a stainless 14x19 but only get up to 5000rpms at 44mph wide open. A 14.8x17 aluminum did the same numbers. I'm also lightly loaded and only a 40 gallon fuel capability.
Depends on how you tend to load the boat fuel and bow monkey wise as to what might be best.
A load with a couple of guys (non MJ size), 60 gallons of fuel, their food, drink and fishing stuff might do good with a 17 pitch stainless.
Now if you got a couple or few MJ's and a lot of stuff, you might need to go down to a 15 pitch.
I'm still dragging my feet as to getting mine tuned in correctly, I know I need a smaller pitch.
That motor did 5000rpms and 42 mph with the 14x19ss or 14.8x17al in my situation.

I am thinking a good 14X17 stainless with some cup!

Should rock the world for ya!!

tsubuki, do you remember approximately what fuel comsumption was? Just wonderin'...and thanks for the info. Ferm looked at the prop when I had it there and said it was way too much but I couldn't remember what he told me to get. I think the stainless I have on there now is a 21p :(

Do you have a working tachometer?...what prop now on motor....what RPM at present?...I agree w/Genie on pitch (17) but believe these deep Vs need more blade, so my vote is a 15 X 17....make it SS if you can...

tsubuki used to own this motor and he said 5000rpm. I assume thats WOT!?! Not sure if that is what you are asking or not when you say "what rpm".

btw, where is the best place to get a prop?

I'm partial to Michigan Wheel stuff when buying new.
Craigslist will on occasion have good used OEM stuff in stainless say $100 or less.
That motor takes the same as the 2000 I've got, 15 spline.

This was the 14x19ss and 14.8x17al fuel burn numbers.
5000rpm-42mph-19.5gph-2.15mpg
3800rpm-30mph-10.5gph-2.85mpg
1250rpm-5mph - 2.5gph -2.0mpg

I'm not sure what the WOT rpm's are supposed to be for that engine. I just know I never achieved them with these two props.

Might be able to talk these guys into a swap. If not it's good to know people that do this work.

We can fix your prop. We offer reconditioning of ALUMINUM PROP'S for $40 to $75 and STAINLESS STEEL PROP'S for $75 to $250 including welding if needed. We can help you increase your fuel efficiency and go faster. You don't have to buy a new prop when I can fix your current prop for the price of a new one or less. We have boat service as well. We offer skeg repair and we sell Stainless Steel,Offshore, Flats and Bass boat props. Summertime is here and we want to keep your boat prop in good working condition. So if you need a prop or boat fixed CALL OR BRING YOUR PROPELLER and/or BOAT to 24700 E Highway 50, Christmas, Fl 32709 or (407) 568-5506 and ask for MIKE.
http://orlando.craigslist.org/boa/2390876983.html

thats awesome information....how did you calculate this? How do you get "fuel burn" numbers? And thanks for the link, that place is right down the road here ;)

If I decide to go new, where do you usually buy?

Would you believe the local hardware store is where I order props from? Not sure if the guy in that department is still alive.
Got a Lowrance LMF-200 gauge, using the EP-10 fuel flow sensor to get the fuel burn numbers.

Thats amazing, guess you haven't had to buy a prop in a bit, huh? Thanks again for the info...

So, it turns out that the old motor I had (91 Rude 200) had a 4 blade prop on it. It says 15x16 on it. I assume that is a 15" blade with a 16 degree pitch!?! :head: If this is the case, I plan on trying it out over this next weekend and see how it performs.

btw, using the 21p prop Saturday I was running 39 mph (gps) at 4200rpm. Seems as though the engine had lots more in it but I didn't push things. Absolutely ran like a charm though. :love:

You're going the right route!
Getting a basis to start makes it a lot less expensive by not buying prop after prop till you find the right diameter and pitch.
The 15x16 sounds like a good compromise. Just be cautious about over revving the engine.
See if FERM can give you the max rpm's intended for that motor.

Tsubaki, I don't get how you went from a 19 pitch to a 17 & didn't increase RPM's or lose speed?

My 200 merc runs a 19 & hits about 5300 at WOT, thats in the mid 40's by GPS.

I've tried a 17 & 17 cupped, the cupped was pretty good, but the 19 is a nicer prop & other than a bit less of a hole shot it hits wot just right.

If you can find a good prop shop most guys will let you try a few props & pick your favorite.

I'll back up the guys saying use stainless, around here an aluminum prop is a sign of a new boater.

Doug

you can also get a non-cupped prop cupped, that adds a bit of push & drops your WOT RPMS a bit, for cheap.

Doug

That would be 4500-5500 for acrossflow OMC, but 5200-5500 is best. Whatever you do do not run it at 5750-5800 for sustained periods of time though. Crossflo engines have an inherent harmonic vibration in them at that speed that has resulted in more than one exploded flywheel from sustained running at 5800 RPM's.

Thanks Ferm...I appreciate the information.

Subtle changes in diameter with the same pitch prop will sometimes achieve your desired performance. Same is true in reverse by changing the pitch but not the diameter. Another facet is a cupped prop, it can make a world of difference.
A good case and point was on a boat my father had years ago. He kept working toward an ideal rpm by buying props then having them repitched, testing them then having the diameter ground. Got it down to two prop sizes, one would overturn the engine, the other would produce slightly less than desirable rpms. I can't remember the size but he ended up getting the same diameter and pitch prop (of one or the other) but cupped. The engine then did what he wanted.
Normally stainless and aluminum props of the same diameter and pitch don't perform the same. There is a relationship (I've forgotten) about matching a stainless props performance to an aluminum one. It seemed like the aluminum props had the ability to flex more, so needing a slightly larger diameter and less pitch to match the stainless props performance.
In my case it turned out that way.

Now, if I will ever get off my butt and get motivated, I'll try to see if I can get mine to the correct rpms with a prop I've had a couple of years.
http://i175.photobucket.com/albums/w.../ssprop005.jpg

well, used the 15x16 over the weekend.....what a piece of crap :cen: I still have no idea which way to go but I am definately putting the SS 14 1/2x21p back on. It outperforms the Aluminum 15x16 which question. I got the following numbers on the 16p prop over the weekend:

25mph - 3800rpm
32mph - 4200rpm

Couldn't seem to push much beyond 4400rpm so I didn't try. Absolutely sucked through the gas like nobodys business. I didn't realize that I have either a bad fuel guage or fuel sender until late on Sunday when I had to call Sea Tow to come and get my butt :bat: I am going to start a separate thread about how to test those two components to see which one is bad.

In a full bog down situation, that engine is capable of drawing 22 gallons per hour.

Is it possible the motor could be mounted too low on the transom?

Pictures and new thread.

Any suggestions on a prop for my V-21 200 Yamaha 2-stroke? I'm new to the serious boating stuff been aroud them all my life now I'm paying attention. The aluminum prop that came with has no stamp on it indicating what pitch or size it is. I hit 48 Mph on the GPS full out if the tack was right it was 5000Rpm and 33 Mph at 4000 Rpm. Does this sound right or not :head:. I want to get to try and find a SS one I'll be doing day trips out to some Islands mostly. I'll be going out with my father tomorrow to see if the tack is on or not hope fully I can pin down some more accurate info.