Outboard HP ??

Gregor_Mic

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Joined
Mar 25, 2013
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Hello!
I'm re-powering my Bass Tracker 1600 TF and I'm looking for some help. Obviously I'm trying to save cost and get the back on the water as soon as possible based on current outboard availability in my area. Here is boat some info before my questions.

16' Boat
7'2" Beam
Boat Plate Max HP rating 115 HP
Boat Weight: 830 lbs.
Transom height: 20"
Previous Motor 90 HP Mercury 2 stroke (topped out around 39 mph on gps.)
Max HP based on calculation 16x7.2x2-90= 140 HP

Questions:
1. I have a few, nice, 150 HP 2 stoke motors around here that are available. Base on the calculation, will that be way too much power or will it work?

2. There is also a newer Mercury 50 HP 4 stroke. Will That work to get me up on plane back onto the lake? Speed is not a huge priority and the two lakes around here are small. I'm looking for 20-25 MPH at a minimum. Note: I really like the reliability and fuel economy of the 4- stroke option.

3. Obviously I'd prefer a 90-115 HP replacement but I just can't find any this time of year. If above 50 HP is too small, what is you recommendation on minimum HP for this model boat.

Thank you in advance for your wisdom and please fire any questions my way if I left out any information you need.

Tight lines!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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your hull is rated for 115hp, any more than that would be too much.

generally you try to shoot for a minimum of 75% of max rating as the lowest HP you would put on the boat, in this case 85hp.. a 50hp motor will get you fishing, however the performance would not be stellar.
 

dingbat

Supreme Mariner
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Nov 20, 2001
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15,414
Horse power is an issue but the bigger issue on a #830 boat is weight.

What is the weight difference between your current 90 HP motor and the motors under consideration?

I'm a firm believer in the 75% rated max. HP. Nothing worst than an under powered boat
 

Gregor_Mic

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Mar 25, 2013
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Thanks Gents! Believe me, it hurts my soul to even be considering a lower HP outboard than I have now but my love of fishing and the water keep calling me. It being teh peak of bass season right now, it's hard to find that i'm looking for without dropping 11k on a new Mer cor Honda. 75% would be 67 so sounds like 70-85 HP will be my bare minimum.
 

Gregor_Mic

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Mar 25, 2013
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Just curious Scott, is the calculation I referenced and have read on this forum not a good guideline to go by?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Just curious Scott, is the calculation I referenced and have read on this forum not a good guideline to go by?

no, the placcard at the back of the boat is what you go with because that is what your hull type is listed at in the USCG database. your max beam is 7.16 feet, your transom is less (about 6.5 feet) which equates to 118, so rounding, 115hp.
 

jbcurt00

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Oct 25, 2011
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It seems your calculations are correct, however, Scott is correct. Its the mfg recommended 115hp max and w that label, you're sort of stuck w it as a max.

Many jurisdictions consider overpowering your boat reckless operation, even when you're boating "responsibly" in all other regards.
 

Sea Rider

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Sep 20, 2008
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12,345
What's the max HP and number of passengers the boat is rated tor ? With how many souls on board do you plan going fishing with ?

The key to run underpowered motors on non heavy hull efficient boats is to dial a spot motor/transom height match along a top prop maximization to a lower prop pitche for motor to run towards its max wot rpm range factory stated. 830 Lbs is not that wow heavy and a 16 footer is not a short lenght boat.

If lightly loaded a 50 HP should be able to power nicely that lenght boat, won't be a speed demon nor break and world speed record, but will take you there at speed powered with a low cost motor.

Happy Boating
 
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