New Motor need prop size

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Harv
Posts: 5
Joined: Thu Apr 12, 2018 5:21 pm

New Motor need prop size

#1 Post by Harv » Fri May 04, 2018 12:21 pm

I have a Bennington 2275 FSI just installed new Suzuki 140 hp 4 stroke on it. The dealer did not have a good choice of different props to try. He put a Black Max 13.25 x 17 on for me to try. The RPM's are good at 6100 but the speed in about the same as the 115 hp 4 stroke with a 13 pitch prop before 27 mph maybe 28 mph now with 25 more hp. Any Ideas?

ron nh
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Location: Litchfield New Hampshire

Re: New Motor need prop size

#2 Post by ron nh » Fri May 04, 2018 2:20 pm

The 4 stroke must have been fairly new? If so then I wouldn't be surprised by those #'s, Probably not enough of a HP increase to overcome pushing a pontoon through the water.
2015 Qwest LS 818XRE Tri-toon w/mercury 115.

Harv
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Joined: Thu Apr 12, 2018 5:21 pm

Re: New Motor need prop size

#3 Post by Harv » Fri May 04, 2018 4:10 pm

The old one was 15 years old

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rancherlee
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Re: New Motor need prop size

#4 Post by rancherlee » Fri May 04, 2018 6:32 pm

Amita 4 blade 15 pitch should work well and they are cheap! I have both a 15 and 17 pitch Amita 4 for my DF140 on my tritoon, use the 17 for light to moderate loads and the 15 for water sports or heavy loads.
1988' Kennedy 20' "Haley's Comet"
Rebuilt 2016 with 25" single strake outer tubes and a 25x23" straked U-tube
2003 Suzuki DF140 - Yamaha 9.9HT kicker - 39.1@6300rpm

Bamaman
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Re: New Motor need prop size

#5 Post by Bamaman » Sun May 06, 2018 2:01 am

RPMs are often a good guide for maxi.um performance. The zuki's are different animals with their planetary gear making them require high pitch propellers. Relatively few Suzuki mechanics are out there t setup them.
Between me and you, the Suzuki 140 horsepower motor has a reputation for good fuel efficiency and troublefree durability. But they are relatively "weak" for their horsepower. On the other hand, Suzuki's 150 horsepower is a whole lot more motor in cubic inches and performance than the 10 horsepower difference--a "strong" 150 hp.
I don't know if your old motor was a 2 stroke, but sometimes more 4 stroke horses are required to match older 2 stroke performance. You may be getting all you can get out of your new motor.
'12 Bennington 24' SSLX Yamaha 150

Harv
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Re: New Motor need prop size

#6 Post by Harv » Sun May 06, 2018 4:32 am

The old motor was a 4 stroke, the thing I am not sure about the dealers setup . I know the Suzuki gear rato is higher so it will run more pitch. When I told him about that he said he didn't know that, He has no Suzuki props and put Black Max props on them I know these are good props but all the diameters are smaller. What I have read was most Suzuki props are larger diameter. I want to buy a SS prop after I figure out what I need ,going to try and talk with another dealer tomorrow and see what he says.

ron nh
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Joined: Sun Sep 21, 2014 1:07 pm
Location: Litchfield New Hampshire

Re: New Motor need prop size

#7 Post by ron nh » Sun May 06, 2018 7:54 am

I glossed right over the Suzuki part. If That mechanic doesn't know they take larger props he doesn't know Suzuki's. Scary.
2015 Qwest LS 818XRE Tri-toon w/mercury 115.

Harv
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Joined: Thu Apr 12, 2018 5:21 pm

Re: New Motor need prop size

#8 Post by Harv » Mon May 07, 2018 3:45 am

I do have lifting stakes on my toons , and can trim the motor out right above three/forth way on the gauge with no slippage . The motor is mounted all the way down I been thinking should it not be raised up one hole . Looking a the Suzuki sheet on the props they list for the 140 hp 13-half x 15 then go to 14 x 17 in Aluminum . SS start 14 x 16 .

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