Recomended prop for 9.8 2 stroke

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Griffin4590

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Its a 9.8 2 stroke on a 12x36 jon boat used for duck hunting. Boat weighs about 125 and is loaded with about 400 pounds of gear. I'd like to keep as much top end speed as i can without losing all my bottom end
Thanks
 
pvanv

pvanv

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Re: Recomended prop for 9.8 2 stroke

What is your WOT RPM now? 9 Pitch would be my first try. The 9.5 pitch might zap the hole shot, depending on how many people/weight you add. Probably best to post this in the prop forum; However, assuming the motor is a Tohatsu/Nissan, there is a prop selector chart at http://www.tohatsu.com/accessories/prop.html
 
TOHATSU GURU

TOHATSU GURU

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Re: Recomended prop for 9.8 2 stroke

Not to disagree Paul, but that boat is going to be an *** heavy pig. I would start with a 7 pitch.
 
pvanv

pvanv

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Re: Recomended prop for 9.8 2 stroke

TOHATSU GURU said:
Not to disagree Paul, but that boat is going to be an *** heavy pig. I would start with a 7 pitch.
Click to expand...

Hmm. Yes... he does have to add weight for crew as well. So it's no longer a 125-pound boat. As I recall, even NASA made a miscalculation with Apollo 13, because the ship didn't have any moon rocks aboard.
 
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steelespike

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Re: Recomended prop for 9.8 2 stroke

With that kind of weight your at the max for the bopat perhaps over.
It will be really hard to get it to plane you would do better with a 12 or 14 42/48/52.
And you would feel safer.Have no Nissan outboard experience but I agree a 7" is close to what you need.
 
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Griffin4590

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Re: Recomended prop for 9.8 2 stroke

Griffin4590 said:
Its a 9.8 2 stroke on a 12x36 jon boat used for duck hunting. Boat weighs about 125 and is loaded with about 400 pounds of gear. I'd like to keep as much top end speed as i can without losing all my bottom end
Thanks
Click to expand...

i'm sorry i should have been more specific the 400 pounds is including the weight of the crew and the dog
 
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steelespike

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Re: Recomended prop for 9.8 2 stroke

Be sure you add up your weight carefully.Did you include the motor and gas tank.Anchor,oars etc these little things can sneak up on you.your still pretty close to the max and little boats have trouble getting up with a load.I think you will be happier with a 7" pitch.Of course you can try what is on there and get back to us with the prop size, max rpm and speed, loaded.
 
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Mi duckdown

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Re: Recomended prop for 9.8 2 stroke

The plate on the boat transom will tell you alot. Most duckhunters are over the weight specs with there gear. I know I am one of them.
 
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Griffin4590

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Re: Recomended prop for 9.8 2 stroke

Boat is not over weight the USCG weight on the tag and i did factor in gas and the motor. as i stated before the boat is loaded with 400 pounds of gear. once and a while maybe 500 pounds but NOT more then that. you guys still think 7 pitch? how many inches?
 
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steelespike

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Re: Recomended prop for 9.8 2 stroke

Have you run it with the present prop? and what size is it?
I do agree a 7" pitch is probably what you need.The diameter will follow. The way to tell what you need is to run it as is and get us the rpm,speed (a tinytach and a gps)and prop size.
Lacking that a performance description loaded and empty.Keep in mind weight distribution,motor trim and height are critical.
 
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