Trolling motor dilemma

[Denny of Pa]

I want a new trolling motor for my 2006 Starcraft model SC166 deep V Alum boat. With all included , Boat, me, gas, batteries, etc. the weight of it is about 1700 Lbs. the Bow sits about 30" above the water. I have read 2 different write ups on trolling motors, one said the motor should sit 9" under the water line the AND the other article said the trolling motors should sit 24' under the water line. the trolling motor that I am most considering is a Minn Kota Terrova w/ I-Pilot. The original equipment that was on this boat when I purchased it used, several years ago had a 71 Lb thrust 24 volt motor guide. with a 52" shaft. Here is my dilemma: The motor I would most like to buy is the 80 pound push, 24 volt, but it only comes in a 45" or a 60" shaft. The 12 volt 55 pound push motor comes with either a 45 or 54' shaft. From my best info read, I should really have a 54" shaft motor, but WHY Minn Kota does not make the 80 lb motor in a 54" shaft is beyond me. ,,, Now according to most of the material I have read on sizing a trolling motor by the weight of the boat, it tells me that the 55 Lb. motor should be adequate for my boat weight.

IF ? what i have read on the motor needing to be just 9" below the water line, I imagine that the 45" shaft 80 lb motor should work. I really don"t want to go to the 60" shaft because i do not what all that shaft stick out of the water IF i only do need it to be 9" down. However IF ? it has to be deeper the 54" shaft would be much better for either motor depth, but in that case then i can only go with the 55 Lb 12 volt motor.

Based on all this information, does anyone else have a similar situation ? AND / OR ANY expert advice would be greatly appreciated.

 

[GA_Boater]

How about just some common sense advice for free.

The shaft should be long enough for the prop to stay under water when the boat is bouncing. Boats aren't stable all that often when fishing due to waves and other boat wakes.

Buy the 60" shaft and find the sweet spot for your boat by adjusting the Depth Collar. A 45" shaft is most likely too short. This is from the Terrova Owner's Manual.

 

[Denny of Pa]

Thank you very much for that response. And quite frankly i had considered some of your points as well. However other considerations are the following: I am probably much older than you, and my physical condition is such that i can not stand for long periods of time, thus making it wearisome to cast out over a trolling motor shaft that is very high above the boat. Therefor i am vacillating on several things, but one of them is NOT the price point. I was shocked when i visited a Bass pro store recently to see that they are only stocking selling a 42 lb troll motor on their alum bass boats.which weigh about the same as mine. And i had ask them " is that really enough power to comfortably move the boat around for 8 hours.? To which they seemed to think so. I have always leaned toward ,,, more is better,,, but the real question is,,,, Is it? Or how much more should it be ? Because even a 55 is more than a 42 on the same weight boat. So if you were me, would or wouldn't you go with a 55 over an 80 on my weight boat?

Still ANOTHER consideration that I had considwered is: How hard would it be to cut the shaft off ont the 60" shaft if i wanted to?

 

[jbcurt00]

I built a boat based on a Ken Simpson design. He has directions posted on his website for shortening the shaft on a trolling motor to fit his small boat plans. So, yes, it's possible to shorten the shaft on a trolling motor, but I don't know how best to cut a composite shaft. I never bothered to cut mine, since it would limit the use on other boats. I'd have to cut the shaft to about 24in to 'fit' the boat I built

But you'd have to make darn sure you aren't cutting it too short. if you're comfortable taking the motor, shaft head unit apart so there's nothing inside the shaft when you cut it.

Google Ken Simpson portable boat

to find his site

Good luck

 

[GA_Boater]

How did the 71 pound thrust TM work before? You do have a frame of reference. Minn Kota does have a TM selection guide HERE and lets face it, if they think a less expensive X thrust is the best choice over a more expensive Y thrust, I would believe them because they are taking money out of the pocket.

They don't recommend a 70 lb. TM until the boat hits 3000 lbs. Your 16' SC166 weighs a lot less.

On shaft length you say it's 30" from the top of the bow to the water line. Add the depth of the bow mount, guessing about 6", maybe less, and the below water penetration using the 12", M-K's minimum, to 24" numbers, gives a range of shafts from 48" to 60".

Using the selector linked above for a 2500 lb. boat, 30" bow to water line gives a 12V 50 lb thrust with 45" or 54". Moving up to an 24V 80 lb'er, the shafts are 45 and 60. I would go with the longer shaft because too short is useless, whereas longer sticks up some, but not by much. I wouldn't cut the shaft because it kills the warranty. Just adjust the collar to drop the motor in deeper water and raise ir for shallower water.

If I were in your shoes, I wouldn't make any bets about which of us is older or in worse physical condition. :joyous:

 

[Silvertip]

History of Bass Pro has been and still is that they generally "underpower" their boats primarily to get the price point down. Many folks (especially first time buyers) are really disappointed with these boats and end up powering "up" down the road. The rule of thumb for a troller is measure from the bow to the water line with the boat loaded the way you use it "most of the time". Add one foot to that dimension and that's the shaft length you need. In your case a 42 inch should work if your measurement is accurate. If not, you will be looking for a longer shaft so get that dimension right. If you routinely fish in rough water, even 12 inches may not be deep enough as the prop may surface in higher waves. As for worrying about the shaft being in the way for casting, you can forget that as well. It is a 3-inch wide head and a one in wide (about) shaft that will not affect casting. If a fish is in-line with the motor you likely wouldn't catch it anyway. I am probably older than you by a bunch and my boats have always had 54 inch shafts to allow for appropriate depth adjustment depending on conditions. That shaft has never been in my way and besides, you are generally casting off the boat at an angle and I suspect rarely directly off the bow.​

 

[ondarvr]

I have the 80# terrova iPilot with 60" shaft.

There is no exact depth required, it can vary depending on conditions, and unless you are in shallow water it can be as deep as you want. So unless you are in shallow water just drop it down until it's not in your way. You can work with it being too long, if it's too short you don't have any options. There is always the option of cutting the shaft down, I haven't looked at my Terrova to see how easy it would be, but on my other trolling motors it's very easy.

If you can afford the higher thrust motor go for it, more power is never a bad thing. Running for 8 hours doesn't really relate to pounds of thrust when just moving around slowly, it has more to with battery size and the number of them.

 

[Denny of Pa]

This indecision on power and shaft length is in part, in consideration of the fact that most of my fishing is done on a somewhat "shallower" lake than many others, of Lake Okeechobee, Fl where the water depth is often time less that 48". So much of the time, a too long of a shaft will be up out of the boat. I seldom fish this lake when it is very windy, and sometimes the biggest chop is that caused by another boats wake. Therefore I really wish i could get a 54" 80, but since not, I am really tempted to go with the 54" 55lb, because I am not too thrilled about continually adjusting the depth on the 60" length.

One other thing that i have been wondering about, since they are so much different than a hinged mount is the question of "stowing" the Terrova motors. How exactly is that motor lifted out of the water? Does some mechanism pull it back in the mounting, ? or do you physically lift it by the top of the shaft?

You all have given me allot of help in this matter and i sincerely thank you all for your input. ,, Denny

 

[ondarvr]

Unless you buy the automatic stow version you physically pull them up, the Terrova isn't much different than any other bow mount in that department. There are big differences between the motors you're looking at, so take some time to understand exactly what you're getting before putting your money on the counter.