Moderated Discussion Areas
ContinuousWave: Whaler Performance
|Author||Topic: PROP RECOMMENDATION|
posted 02-06-2003 04:58 PM ET (US)
Recommendations would be welecome for prop on 200HP Yamaha/99 on 88 20'Outrage. Thanks in advance
posted 02-06-2003 05:59 PM ET (US)
Some questions need to be answered before any help could be offered.
1) What size/type is on it now (pitch, diameter, material #blades)?
2) What is the current RPM at WOT?
3) What is the mfg suggested operating RPM at WOT?
4) What would you like the new prop to do (better hole shot, more efficent cruising, pulling water toys/skiers)?
With this information we can better help you out. Anything advice without it would not help at all.
posted 02-06-2003 06:06 PM ET (US)
I have a 1989 20' Outrage with a 1994 200hp merc.
my prop is a 14 X 19 cupped ss prop and seem s to work great.
My wot is about 5700rpm and fully loaded with gas and people I get about 44 mph
posted 02-06-2003 06:36 PM ET (US)
No prop yet....I'm re-engining the boat and the motor is coming without a prop. I heard through other sources that a 15 1/4 - 17, stainless steel might work well also.
posted 02-06-2003 06:38 PM ET (US)
Sorry....neglected to mention that will it will be for general use, ie fishing, skiing now and then, cruising around.
posted 02-07-2003 12:44 AM ET (US)
What is your target boat speed?
That is the lower unit gear ratio of your engine?
posted 02-07-2003 10:30 AM ET (US)
Gear ratio is 1.86, target boat speed isn't as important as making sure the engine is within recommended maxRPM range (5500) with a prop for general purpose boating. Some boats are easier to push than others, not sure what could be expected for 20' 89 outrage.
posted 02-07-2003 11:02 AM ET (US)
Bear....I owuld think a 19 would be the one. Reason being my 20 Hydra is running a 19 with a 225 that turns 6k WOT. Your boat is lighter and with a 5500 redline, she should be able to hit it or come real close. 17" would be for a 150 in my eyes.
posted 02-07-2003 05:46 PM ET (US)
I was thinking a 19" pitch Merc Mirage Plus. Maybe even a 21" but that maybe a bit to tall.
posted 02-07-2003 07:03 PM ET (US)
I agree with 19" pitch. Top speed should be about 50mph, at least that's what Mercury's prop chart shows. Gear ratios are the same.
I strongly recommend a vented performance grade, bow lifting, SS prop, either by Yamaha or Mercury (has hub to fit Yamaha). Because the boat is light, and fully powered, I'd go with a Merc Laser II. I run those on both of my Whalers.
posted 02-07-2003 10:54 PM ET (US)
You can estimate the boat speed potential if you know the weight, the horsepower, and the hull factor.
For a 20-Outrage and 200-HP it predicts around 43-MPH.
Once you have a target speed, you can use the PROPELLER CALCULATOR to work out the pitch.
The 19-inch pitch propeller come out to about 48-MPH. A 17-pitch works out to about 44-MPH..
posted 02-08-2003 06:59 AM ET (US)
Thanks to all for the info...much appreciated!
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