Author
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Topic: TEMPTATION 2500 with Twin Suzuki 175-HP
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venicewhaler |
posted 11-19-2009 07:41 AM ET (US)
Especially for those Temptation connoisseurs: can a normally loaded [Boston Whaler TEMPTATION 2500] reach plane with only one Suzuki 175-HP engine, if the other engine is on failure?
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jimh
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posted 11-19-2009 09:05 AM ET (US)
I don't see where in the Boston Whaler specifications the minimum horsepower needed for satisfactory operation with a light load for a TEMPTATION 2500 is given. We might infer that specification from a boat of similar hull design and weight, a REVENGE 25 W-T Whaler Drive. A REVENGE 25 W-T Whaler Drive is rated for a minimum horsepower of 115-HP.On the basis of comparison with a REVENGE 25 W-T Whaler Drive, I think you can say that a TEMPTATION 2500 (assuming Whaler Drive) can reach plane with 115-HP. Therefore, we can assume that a Suzuki DF175 four-cycle engine ought to have enough horsepower to push the TEMPTATION 2500 to plane. However, we must also consider the propeller selection. If the Suzuki DF175 is equipped with a propeller that has been selected for optimum speed when running with twin engines, the propeller load may be too great for a single DF175 to push a TEMPTATION 2500 on plane. You may have to reduce the propeller pitch to accomplish this. |
venicewhaler
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posted 11-19-2009 10:16 AM ET (US)
thanx jim, temptation has a factory installed WD and I do agree it performs really close to revenge 25 wd of the same year (87). of course props selection is very important: usually suzuki has larger props, 16 dia vs. actual 14,25, and shorter pitch (actual being 21") therefore I understand it planes easier but top speed is lower. Actually with 2*225 88 OMCs I can see 51 mph with small load and I'm expecting around 45 mph with half tank and 5 persons aboard with the new rig |
newt
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posted 11-19-2009 10:53 AM ET (US)
A non-whaler drive Revenge 25 can get up on plane with a single as low as 130 horsepower. A few months back there was a thread about it that you should be able to dig up with a search. The boat in question was powered with twin Etec's.From first hand experience, a single old Johnson 150 will get the 25 Revenge up on plane and max out around 30 mph at 4000 rpm. This is achieved with the engine propped for normal operation with both motors running, as you could guess from the low max RPM achieved with only one engine. I don't know how much extra horsepower the whaler drive requires, but my guess it that 175 horsepower will definitely do the trick. |
TransAm
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posted 11-19-2009 03:44 PM ET (US)
A single, 175 HP Suzuki engine should be able to plane off a 25' Temptation, but it will not be happy doing so propped for twin engine operation. The single engine will be working very hard to maintain plane and it would not be recommended for an extended period of time. One way to allow the engine to turn more RPM's (reducing the running stress on the engine) would be to trim the engine to the point where the propeller begins to slip. This will require constant jockeying of the trim and throttle depending on water conditions. |
venicewhaler
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posted 11-19-2009 04:34 PM ET (US)
Transam, the use of a single suzuki df 175 is intended just in case of failure, hopefully not too far from home. Going twin is worth only if you can plane on one motor if the other is gone. Please give advice if 45 mph top speed will be a fair value and also suggest your choice of props among these: - 3 x 16 x 17 - 3 x 16 x 18,5 - 3 x 16 x 20 - 3 x 16 x 21,5 - 3 x 16 x 23 - 3 x 16 x 24,5 thanx and best regards, vce |
TransAm
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posted 11-19-2009 05:04 PM ET (US)
45 MPH is certainly achievable, perhaps a couple MPH more. As for props, I do not have much experience with respect to 4-stroke engine propping. With twin 2-stroke 175 HP engines I would expect you would want to be in the 17" pitch range. However, the gearing of the Suzuki's is much higher numerically, and they should be able to swing a larger pitch prop, perhaps as high as the 21.5". The best advice I could offer would be to prop the engines for the upper end of the operating range (6,000-6,100 RPM) in the event you need to operate on a single. However, with newer Suzuki's, there should not be much of a need. |
Hoosier
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posted 11-20-2009 08:32 AM ET (US)
[Suggested moving to another website in order to use a propeller calculator.--jimh] |
jimh
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posted 11-20-2009 09:51 AM ET (US)
David--We have the same resource here: http://continuouswave.com/cgi-bin/propcalc.pl |
Tom W Clark
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posted 11-20-2009 01:32 PM ET (US)
Daniele,With the Suzuki DF175s, you will want to use a pair of the three blade 16" x 23" Suzuki propellers. |