Prop

[jchief]

Finally got the f150 broke in and ran it WOT for a while and think I need to play with props. WOT gets me to 45 mph and 5200 rpm. Need to be turning about 6000 rpms. What do I need to do to get there? The current prop is a 3 blade and the only markings on it are 21m.

[Shawn Braquet]

I'm no prop guy but you should at least be able to run a 23 and maybe even more while staying with the 3 blade

[all star rod]

What size type boat are you running it on?
BTW, I can turn mine with a 19" 3 blade power tech prop, Yamaha 4 stroke 150, 44 gallons of fuel, 3 men with all gear, boat dry weight 1,700 pounds to my max rpms of 6K doing 48-50 mph.....

[jchief]

It is on a 210 Frontier. The load was 3 people, 40 gallons of gas and 2 men and gear.

[all star rod]

Suprised you cannot turn it more with the 19". I would think if you put a bigger prop like a 21" you would turn it even less RPMS; however, I may be wrong.

[Ray]

I can run 50 at 6K rpms with 60 gal. gas, 2 tackle bags, full ice chest, me and a big azzed Texan, in rough water, with a Yamaha F150.
Boat is 19 ft. and weighs 1960 lbs dry.
But it caint get off an oyster reef without everyone getting out and pushing...

[Ray]

Just went and looked. It is a 4 blade Power Tech, 19 pitch.
It don't say the size, but I measured 14 inches across.

[jchief]

Guess I need to find a 19P to try on the boat.

[all star rod]

With the 19" prop not sure if you will get more speed. However, to me you should want to be able to reach max or very close to max RPMS on your motor.

[simplepeddler]

Check out "prop gods dot com"
they have calculators that will give you and idea of speed at the 6000 mark with that 19 Pitch prop.

you will need the gear ratio of the lower unit I think.
my suggestion is trying lifting the motor some first. Half inch at a time.

then next would be downsizing the prop pitch

[Ray]

I can get the model number off the prop tomorrow if you want. Just send me a PM so as a reminder.
You should be able to do at least what I can do, your boat is a little lighter than mine.
My boat is matched by the manufacturer for the Yamaha. It did exactly what they said it would do.
During my break in, the dealer wanted me to run at WOT twice, for 5 minutes each time. I had to run
at different rpms for 5 minutes each. My wife and I took off from 210 and ran the ship channel, West Cove,
West Fork, to the jettys and back up the ship channel, Old River, East bank of Big Lake, LNG, back into
the ship channel and up to Prien Lake and Lake Charles, then back to Prien Lake.
5 hours. Did it again the next day and got my 10 hour break in done. Then the dealer said to run it how
ever I want. It won't hurt her.

[Ray]

Does your boat have trim tabs?
If so, you may have them too far down.
To get to 6K rpms, I have to have my tabs all the way up and trim the motor just right.

[jchief]

Originally Posted by Ray

Does your boat have trim tabs?
If so, you may have them too far down.
To get to 6K rpms, I have to have my tabs all the way up and trim the motor just right.

Don't have trim tabs on it or a jackplate. Bonna see if I can find a 19 to try and see what that does and go from there.

Thanks for the info

[Ray]

I don't have a jack plate either. When I am at WOT, I have my tabs all the way up.

Here is the number off of the prop.
Power Tech SCE4R19PCL200
ptprop.com

http://www.ptprop.com/component/opti...d,4/Itemid,60/

This is the one I have: http://www.ptprop.com/component/page...art/Itemid,46/

[Montauk17]

For every degree of pitch you go up or down you will gain/loose 200 rpm's. Doing the numbers you will need a 17p. I would go with a mercury mirage,its hands down the best prop for a bay/offshore boat.

[jchief]

Originally Posted by Montauk17

For every degree of pitch you go up or down you will gain/loose 200 rpm's. Doing the numbers you will need a 17p.

That is what I was thinking also. Appreciate the input. Will see if I can find a couple to try out in the next few weeks.

[Montauk17]

Originally Posted by jchief

That is what I was thinking also. Appreciate the input. Will see if I can find a couple to try out in the next few weeks.

No need for testing out differant props,go with the 17p mirage you will love it.

[Nasty]

I have a Yam 150 2-stroke turning a powertech 3-blade 15.25 x 19. My blazer bay 1960 hits 49-51 at wot (5500 rpms) while loaded. I don't think the 4-stroker can spin the bigger diameter prop like a 2-stroke can. So my guess is trying a 14 x 19 or 14 x 17 prop. I called the powertech people. They helped me narrow down my choice of prop. I got it right the first time. They were very helpful.

[evis102]

Mercury Revelution 4, 17p without jackplate, 19p with jackplate, no 3 blade prop will push my 22ft Triton any were close to what the 4 blades will and I have tried $1000 props.

[Dink]

I went from a 19 to a 17, have same top end, but at a higher rpm. Big difference in hole shot! And boat handles completely different!!! She's way up out of the water now, and before it was more like driving g a tugboat........


Something seems off with all these numbers tho......most are getting over 50 MPH???? But your not even close and need less pitch to be in your rpms.......something sounds a little off here.......