kicker motor sizing

[gbill512]

Does anyone know if there is a formula to select the size of a trolling motor?

I have a 19ft open bow fiberglass fish/ski and was thinking about buying a small outboard. How many horses do I need?

[skipper19]

9.9 is what I have for a 22ft-4000 lb center console and it does ok. I think that it is the minimum for that size boat. I sometimes could use just a little more for the heavy seas and wind over 20 mph but it works. 9.9 has the added advantage of going on horsepower limited lakes too if you want to swap it around to a smaller craft and fish lakes like Hemlock.

Mark

[big easy]

I run a Yamaha 8hp High Thrust on my 23 SeaCraft which weighs 4200 lbs and is about 5400-5500 pounds with three guys,fuel,and tackle. It pushes the boat with no problem.

Wide open is 6mph.I tested it out a couple weeks ago,and it performed perfectly,from dead slow to any salmon speed.

I also have a 22' Trophy with a 9.9 Yamaha on it.It's a lighter boat,but still gets the same speed 6mph wide open.

There is no difference between the 8 or 9.9 for pushing the boat.

Horsepower only comes into play when your hull hits its planning speed,and none of these kickers will come close to getting you on plane.

The 8hp is plenty for your boat.

[gbill512]

Thanks for the info.

[Trap Jaw]

I wanted to add that, like big said, you can get away with a lot less motor, less weight, and less money by going with a smaller motor. I think my boat is more in the size range of what you have. It is an 18' wellcraft crnter console. We just put an 8hp yamaha 4 stroke on it and after running it we realized that we overkilled the motor. We should have gotten the 6hp. Top speed with the 8hp was 6mph. I don't think we would have lost that much more by going to the 6hp, other then 10-15 pounds. Maybe a little, but it's only for trolling and how fast do you need to go there? 2-3mph.

On my old boat, a 16' open bow fiberglass, everyone told me I needed a 9.9. I put one on and used it for quite some time until it started giving me problems. I found an old 4hp Merc and replaced it. I lost 2 mph on top speed(9.9 topped out at 7) but I gained on the fuel. I typically used 4 gallons of gas on an average trip with the 9.9, with the 4hp it dropped to 2 gallons per trip. Quite a bit over an entire summer.

[W.W.IV.]

Guess I'll jump into this one,you get out there on a windy day and your motor lets you down on that 20-23fter that 8 hp. isn't going to cut it. You still need enough HP. to steer the boat and get you home safe. Smaller may not be better.

[skipper19]

What W.W.IV. said is valuable. I echoed that response as well earlier here. Yes the smaller horsepower will MOVE you, and so will an electric trolling motor. Bass boats weigh plenty too and they can move with any troller, BUT, ask them if they go offshore in heavy seas or in offshore winds over 15 to 20 mph. When you have a deep V hull, or add to it, a high profile such as a top or enclosure and a net sticking up in the air, in moderate seas (2-4 ftrs) you will have a hard time even at full throttle to maintain course and consistent trolling speed.

All this being said, I will take a guess that when you say you have a 19 foot open bow, probably a low profile boat, maybe not so much draft, and depending on how much load you have (cooler with Beer, ice) etc, I could say it depends on the body of water too....well lets just say it depends on a lot of factors to consider. If you only troll on nice low wind days then get a little 7.5 or less hp and save the bucks on engine and fuel. My only recomendation on the engine would be it have 2 cylinders for smooth operation (less vibration and usually quieter) and it be a four stroke for economy. Lots of stuff to consider but don't let it be too complicated, after all you just want to troll with it or have it get you back in a pinch when the main engine quits for some unknown cause.

Mark

[Tripleduece50]

My 2 cents...I have a pretty light aluminum deep v. Walk thru windsheild Blue fin. I have a 8hp fourstroke and love it. No prob getting down to speed and good for when the winds pick up if needed. It will push the boat around 7mph if needed. Works great for me TD

[Hookedup]

I have a Yamaha 9.9 4 stroke High thrust on a 23 ft parker. My boat is heavy and with the motors of the back it is at least 27 ft long. Going into the wind on the Sunday of the scotty we had some big waves and I never had it at full throtle. I had a 15 hp Merc 4 stroke Kicker on my 19ft Alumacraft and that did not push that 19ft boat as well as the 9.9 does my big boat. 6 to 7 MPH is all you will get out of any of them if the motor is not big enough to get the boat started on plane physics wont let it happen.

[jimski2]

My 9.9 Honda brought me home at 6.5 knots from 10 miles out.

[big easy]

Again I have to say that the T8 is plenty for your boat.I just returned from 11 straight days of fishing on lake O,and the T8 pushed my heavy 23 footer,into several days of three footers without a problem.

My boat is very heavy(around 5400-5600 lbs)and has a very deep V (24 degree deadrise).Boats with deadrises like these take a lot of horsepower to get moving.I wouldn't matter if i had an 8 hp,9.9hp,or 15 hp kicker,none of them would out perform each other.

I've run all those sizes,on all my previous boats,and they all did the exact same job.The fifteen hp did no better of a job than the T8 does,and it was on a lighter boat.None of them exceeded a top speed of 7mph.,and all did the same job,when it came to pushing the boats at salmon speeds.

I don't care what size kicker you use,when it's real nasty they're all going to be difficult to troll with.It's not because they won't push the boat,but more so that it's difficult to hold course when going into big waves.Let's face it,even I/O's and big outboards are a pain in the a-ss when trolling into big waves.

If your ever up in Olcott,shoot me a pm,and if I'm there,you're welcome to take a ride with us and see how well the T8 does the job.