# Transom Height (Do I need a 20 inch or 25 inch motor?)



## LibertyCall (Oct 3, 2007)

I have a 19 foot flats boat I bought without a motor. Previous owner claimed it had a 150 hp on it, but that is all I know. Manufacturer is "Frost", which is no longer in business. The hull is fairly flat at the stern, and the distance from the top of the motor bracket to the bottom of the hull is 20 inches. However, there is a V that extends down another 5-6 inches from there. This V stops about 5-8 inches short of the transom, and this is where the transom plug is located. So the actual keel and lowest point of the hull is around 25 inches from the top of the motor bracket. I am shopping for a 90-115hp, but I have no idea what shaft length I should be shopping. Like most everyone these days, I am working on a budget, so I can't really go drop it off and have it powered. Any advice is appreciated.



Doug


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## Snagged Line (Sep 30, 2007)

Any chance the previous owner knows where the old motor is, so You can get measurements and specs for the motor you will need.

also start looking through "used boats for sale" sites for Boats like yours and try to contact the owners with questions about motors etc. You might find someone with a boat like yours that is willing tohelp you out.


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## LibertyCall (Oct 3, 2007)

No, PO is long gone. Thanks for taking a stab anyway.


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## DOUBLE "D" & LV (Oct 2, 2007)

Measure the height of the transom to see what you need.


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## LibertyCall (Oct 3, 2007)

That is the point of the question...do I measure to the bottom of the transom or the bottom of the keel? I.E. do I include the V that extends below the transom?


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## Patriot (Jun 4, 2009)

Traditionally you measure form lowest point on keep to top of transom. Your boat would need a 25 inch shaft motor. 

Now here's where you can get sporty. Does theboat have a jackplate or running pad installed?

Do you want to run this boat in very shallow water? Do you want the boat set up for speed or ease of use/functionality?

If its speed and skinny water,you can still go with 25 in shaft but will need a jackplate to move the engine up and down depending on your setup preference.You will also need a modified lower unit with a low water pickup and a water pressure guage. If you just want to knock around the shallows , then you won't need the jackplate or modified lower unit and the 25 inch will do. Make sure you get the correct prop for the motor/boat combination.

If in doubt, call Kenny at Emerald Coast Marine.

Good luck.


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## LibertyCall (Oct 3, 2007)

Patriot,

Thanks for the info. Time to sart shopping for a new motor! Looking for a 2003 or later Yamaha 90 or 115, 25 inch shaft in case anyone has something that will work.

Doug


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