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ChocoLab

Force 9.9 hp propeller question

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Hello all, Well finally have my 14' grumman up and running, but whacked a rock this weekend on it's shakedown cruise and dinged up the prop pretty good. I'm trying to find a replacement prop but don't know much about these things. The owners manual says a 8" X 8 1/4" prop, but haven't been able to track one down. The motor is a 1988 9.9 hp Force. Can anyone help?

 

Also, as far as I can tell this is the same motor as a 15 hp, same weight, stroke and bore etc.. I've read that you can up the hp on these small motors by swapping carbs or reeds. Anyone a small outboard mechanic can lend a bit of advice on this? She goes about 15 kt w/ just me and basic safety gear/fuel and will get up on plane but porpoises a bit. Won't plane when fully loaded to capacity of about 6-700 lbs. just looking for a cheap solution (if it exists) to up the performance a bit. I know this might be a shot in the dark, so thanks!!!

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For Force, this kind of stuff might be hard to come by. It can be done, what you really need to do is get a parts manual of the 9.9, and the 25, and compare part numbers, and whatever is different, change that part out.

 

Finding parts is more difficult, considering "force" changed hands, and most current mercury places stray away from carrying too much in terms of parts, and try and discourage them doing service.

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Try Michigan Wheel

SKU:#072123

 

About $125, fits the 8HP but I think they are the same. West Marine might help ya. I had a 1987 Force and bought a prop there 5 years ago.

 

Just search Force parts and you'll get to I boats.com, follow your nose from there. Those motors were before Mercury lower ends so they do not have thru the hub exhaust typical on Mercs, but they are available. Did you try taking it to a prop shop? They can do wonders for about $50.

 

By the way, I used to live in Hudson MA

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View PostTry Michigan Wheel

SKU:#072123

 

About $125, fits the 8HP but I think they are the same. West Marine might help ya. I had a 1987 Force and bought a prop there 5 years ago.

 

Just search Force parts and you'll get to I boats.com, follow your nose from there. Those motors were before Mercury lower ends so they do not have thru the hub exhaust typical on Mercs, but they are available. Did you try taking it to a prop shop? They can do wonders for about $50.

 

By the way, I used to live in Hudson MA

 

 

Thanks mike, the owners manual says the prop is an 8" X 8 1/4". This has been a lot tougher to find this prop than I could have imagined.

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I forget which way it is stated on the prop(pitch or diameter first). If your motor runs well into the middle of it's RPM range with that prop, you can likely go any size SLIGHTLY smaller in diameter, (if 8-1/4 is diameter, you can easily go 8". can ONLY go smaller on Diameter) and within 1 degree of pitch, and it will not hurt nor hinder the motor.

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