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13 sport water spray issue
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| Geo |
Posted on 03/29/12 - 5:06 PM
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Trying to modify that engine so its output is 55 h.p. sounds like wack-a-mole for sure. Go ahead and try it, but if your boat is still performing at 30 m.p.h., I'll bet you anything that the engine is not the problem and it is the boat's hull being warped that is the issue. Is your boat nose-diving? If so, it may be warped. You can not see the warp from the vantage point of a trailer. You need to flip the boat over and check the hull for delamination. If there is delamination, you will be able to detect large "soft spots" in the hull where the outer hull is no longer bonded to the inner hull. Also, there is no way on earth that you would ever need a 19 inch pitch prop for a 40 h.p. on a 13 foot Whaler. Normal would be about 13 or 15 inch.
Edited by Geo on 03/29/12 - 5:12 PM |
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| Tom W Clark |
Posted on 03/29/12 - 6:36 PM
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...there is no way on earth that you would ever need a 19 inch pitch prop for a 40 h.p. on a 13 foot Whaler. Normal would be about 13 or 15 inch.
Nope. A 2000 Johnson 40 on a 13 footer would normally use a 17" pitch prop but, of course, that also depends on exactly what model of propeller you are talking about. A 13" pitch prop on this boat, of any brand or model, would be a disaster.
There is NO WAY you can generalize about what pitch is needed simply by horsepower. Different outboards of the same horsepower use different gear ratios, have different engine speed ranges and use different size gearcases.
Be very careful when making generalizations and never bother to offer propeller sizing ad=vice unless you explain exactly what model of propeller you are talking about.
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| Slickityd16t |
Posted on 03/29/12 - 8:38 PM
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Geo wrote:
Trying to modify that engine so its output is 55 h.p. sounds like wack-a-mole for sure. Go ahead and try it, but if your boat is still performing at 30 m.p.h., I'll bet you anything that the engine is not the problem and it is the boat's hull being warped that is the issue. Is your boat nose-diving? If so, it may be warped. You can not see the warp from the vantage point of a trailer. You need to flip the boat over and check the hull for delamination. If there is delamination, you will be able to detect large "soft spots" in the hull where the outer hull is no longer bonded to the inner hull. Also, there is no way on earth that you would ever need a 19 inch pitch prop for a 40 h.p. on a 13 foot Whaler. Normal would be about 13 or 15 inch.
I had the hull upside down last year for a bunch of gelcoat repair. Their is nothing wrong with the hull other than the poor color matching I did on the bottom.
1986 13 Sport - 40 hp Smoker |
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| Geo |
Posted on 03/30/12 - 5:24 PM
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You wrote : "Nope. A 2000 Johnson 40 on a 13 footer would normally use a 17" pitch prop but, of course, that also depends on exactly what model of propeller you are talking about. A 13" pitch prop on this boat, of any brand or model, would be a disaster."
Based on my use for 42 years of a 13 ft Whaler, starting with a 40 h.p. Merc in 1970, and then shifting to a 50 h.p. Yamaha in 1986, I'm surprised you believe a 17 inch pitch prop would be correct, but then again, all motors are different, as you point out. Have you tried a 17 inch prop yourself on that boat?
For my Yamaha I am using a 15 inch three-blade aluminum prop and it does fine for 1-3 people in the boat, without the motor running at too low or high r.p.m. I'm just passing along my experience. The 13 inch prop would do O.K. for water skiing but would allow the motor to run at too high an r.p.m. for general use. How a 19 inch prop would be appropriate, I do not know. It might work O.K. for a very light person alone in the boat. Questioning the use of the 19 inch prop was my main point.
Edited by Geo on 03/30/12 - 5:28 PM |
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| Tom W Clark |
Posted on 03/30/12 - 6:04 PM
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I'm surprised you believe a 17 inch pitch prop would be correct...
Why?
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| dgoodhue |
Posted on 03/30/12 - 7:28 PM
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Your 50hp Yamaha has a 1.85:1 gear ratio and the motor in question has 2.42:1. Your Yamaha if it had a 2.42 gear ratio would require a 19p prop of the same style to go a similar speed as the 15p you currently have.
Dave |
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| Slickityd16t |
Posted on 03/30/12 - 8:27 PM
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dgoodhue wrote:
Your 50hp Yamaha has a 1.85:1 gear ratio and the motor in question has 2.42:1. Your Yamaha if it had a 2.42 gear ratio would require a 19p prop of the same style to go a similar speed as the 15p you currently have.
Exactly why you can't just look at horsepower. Also gearcase size are large factors, 4-strokes have a bigger case than in the past so prop diameters are different than before.
Edited by Slickityd16t on 03/30/12 - 8:28 PM
1986 13 Sport - 40 hp Smoker |
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| Tom W Clark |
Posted on 03/31/12 - 7:24 AM
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The old 1970 Mercury 402 (40 HP) used a 1.7:1 gear ratio.
The 2000 Johnson 40 uses a 2.42:1 gear ratio.
If you do not understand the relevance of gear ratio, then let's use this as an example.
For a Sport 13 to reach 36 MPH (which is what Whaler said it would do with 40 HP) with the 1970 Mercury 402 and its 5300 RPM redline and 1.7: gear ratio will require a propeller with 13 inches of pitch, assuming about 6 percent propeller slip.
For the same boat to reach the same speed with the 2000 Johnson 40 and its 5500 RPM redline and 2.42:1 gear ratio will require a propeller with 17.8 inches of pitch, assuming the same amount of propeller slip.
I know from personal experience that the Stiletto Triad tends to have low calculated slip so the 17 inch pitch model is what I recommend.
With the 19 inch Triad, the 2000 Johnson will only reach about 4900 RPM at WOT.
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| Slickityd16t |
Posted on 04/03/12 - 11:44 PM
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Prop came in today, of course I didn't know the hub was separate.
1986 13 Sport - 40 hp Smoker |
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| CES |
Posted on 04/04/12 - 3:40 AM
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Slickityd16t wrote:
Prop came in today, of course I didn't know the hub was separate.
???? Details please.
Cliff
1966 13' Sport with a 1993 40hp Yamaha 2 Smoker |
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| dgoodhue |
Posted on 04/04/12 - 6:14 AM
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CES wrote:
Slickityd16t wrote:
Prop came in today, of course I didn't know the hub was separate.
???? Details please.
The hub isn't included. This Allows the prop to be more universal so it would fit OMC, merc, Yamaha, ect lower units and all you would need to do is change the hub.
Dave |
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| Tom W Clark |
Posted on 04/04/12 - 7:36 AM
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I cannot believe a propeller vendor would have sold you the prop without advising you of the need for the hub. Even online vendors usually force you to select the appropriate hub or check a box indicating you don't need one.
You need the C-012 Guardian SQ-LOK hub kit
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| Slickityd16t |
Posted on 04/04/12 - 11:39 AM
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Tom W Clark wrote:
I cannot believe a propeller vendor would have sold you the prop without advising you of the need for the hub. Even online vendors usually force you to select the appropriate hub or check a box indicating you don't need one.
You need the C-012 Guardian SQ-LOK hub kit
I'm right there with you on that.
Glad I ordered the right one.
1986 13 Sport - 40 hp Smoker |
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| Slickityd16t |
Posted on 04/29/12 - 10:58 PM
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Finally took her out today with triad prop, my truck was down all month. Anyway was able to hit 34.3 mph @ 5800 with the motor trimmed up. With it trimmed down where it doesn't cavitate terribly easily 27-28 mph @ 4200-4400. The motor is in the second set of holes. 1 person 190lbs, 7 gallons of fuel, tank is under middle bench.
Edited by Slickityd16t on 04/30/12 - 12:06 PM
1986 13 Sport - 40 hp Smoker |
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| Slickityd16t |
Posted on 05/01/12 - 6:12 PM
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I still seriously wonder if the 14 gal fuel tank in the middle of boat has anything to do with the issues.
1986 13 Sport - 40 hp Smoker |
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