Thrust needed for small boat?

[keninaz]

I have had bigger boats in salt water but never a smaller boat on a lake nor have I dealt with an electric trolling motor.
My question regards thrust. I am in the process of buying a 12 foot aluminum boat. It's an old gamefisher, V nosed but I am sure from the pix it's a flat bottom.
For the most part it will be just me fishing out of it and maybe one other person.
The motor with it is a Min Kota 17# version. I am not looking to water ski here but is that enough for the task on a smaller lake?

 

[jspansel]

Re: Thrust needed for small boat?

I'm sure it will get ya around... I have a 13' aluminum and have an older 30# minn kota that gets it moving pretty good with me and my dad in it.

I am getting a new 45# for it though now just to get a newer unit on there. The 30# runs fine, just upgrading

I have not felt what anything under 30# feels like though so I cant say for sure... I wouldnt wanna go under that though.

 

[keninaz]

Re: Thrust needed for small boat?

OK, thanks. I was thining 17# sounded a little weak. I may however keep the motor as a spare just in case?
Once I secure the boat I will look for another motor after Xmas is over.
Any brands your recomend or to stay away from?

 

[lncoop]

Re: Thrust needed for small boat?

Sounds like you intend to use a TM as your sole means of propulsion. If so, you'll be disappointed with 17 lb thrust. Look for a minimum of 30 with 42 being optimal. Should be able to buy a brand new Minn Kota basic hand controlled model in that range for $200 or less that you'll be contented with for many years. Around here they can be found gently used for $100 or less. Not sure if that's the case in your neck of the woods, but it would be worth a look.

 

[keninaz]

Re: Thrust needed for small boat?

OK and thanks.
Small boats and such seem to be all over up here in the mountains as we have lots of little lakes.
I will look around and see what I find in the way of a motor once I get the boat secured.

 

[jspansel]

Re: Thrust needed for small boat?

I use mine as my sole means of moving the boat. The 30 gets us all over the lake all day... Minn Kota seems to be a trusted brand. Motor Guide seems to get good reviews as well. For the brand new 45# I think I am getting it for right around $190 something.

I think the only reason I am getting the extra thrust, is because the older model 30# and the newer model 45# both have the same battery drain rating for thrust/time. So I figured I can get more thrust for the same battery time, why not?

 

[wire2]

Re: Thrust needed for small boat?

......

I think the only reason I am getting the extra thrust, is because the older model 30# and the newer model 45# both have the same battery drain rating for thrust/time. So I figured I can get more thrust for the same battery time, why not?

Electric motor manufacturers are notorious for bending the calculations for coming up with ratings. Not necessarily "lies" but still a stretch. Phrases like "Peak HP" or "Peak thrust" come to mind.

There's no free lunch, xx watts of energy from a battery will make yy pounds of thrust, with the only variable being motor efficiency up or down a couple percent.

 

[keninaz]

Re: Thrust needed for small boat?

Yes I know, I spent my career in the electrical and electronics industry.
The facts are you can't get something for nothing.
Now the new variable digital type motors do draw less amps for the power they put out.
But I can buy the older models and buy a bigger battery a lot cheaper too.

 

[keninaz]

Re: Thrust needed for small boat?

Well someone told that trolling motors are not like gas motors and the props are set up for trolling and not speed.
So therefore as the motors are set for about 5 mph I have to now figure out just what my used 12' Mirrorcraft V hull can use correctly.
So going from a 30 to a 40 or 45 may be of little benefit on a lake.
Oh well, it may save me some money.

 

[Silvertip]

Re: Thrust needed for small boat?

The newer digital motors draw less current only when operated at less than full speed. At full speed it doesn't matter whether you have a digital motor or not as they both draw the same or very near the same current. That is provided you are comparing two motors of the same thrust rating.

 

[keninaz]

Re: Thrust needed for small boat?

Yes but at their price they are too much for my retired budget.
It appears that a 30# will do me and I am still not certain I would benefit any by going to a 40#.

 

[fishrdan]

Re: Thrust needed for small boat?

It appears that a 30# will do me and I am still not certain I would benefit any by going to a 40#.

You won't miss the extra power unless you NEED it, battling waves and wind, moving quickly. I could probably "get by" with a 30#, but happy I have a 42#.

 

[keninaz]

Re: Thrust needed for small boat?

And that I must assume is the key.
A 30 or maybe even less is fine for the boat. But load it a little heavier or fight the wind and water coming in will require more power.

 

[jspansel]

Re: Thrust needed for small boat?

I think the biggest thing I was told like stated above, they will both get up to the same speed, just the higher lb thrust will get there faster. And if you are in windy conditions, thats where the higher thrust will help out.

 

[Huron Angler]

Re: Thrust needed for small boat?

I've been very happy with my 30lb thrust Minn Kota on my 12' semi-V tinny.

I've even gotten lots of use out of it on my 16' Starcraft, it pushed it against a 2-3mph current just fine. In some wind it's no good on a bigger boat though.

It will push the 12' rig w/ two guys and gear about 4mph and that's plenty. Best thing to do is make sure you have a fully-charged deep cycle and keep it topped off on a trickle charger.

 

[madman2021]

Re: Thrust needed for small boat?

I grew up on a electric only lake and we've tested many different motors. Since your boat is small and light the best motor for your application would be a 30 lb thrust minn Kota with a 2 blade prop. Youll see fast speeds(talking electric) and long operation. Those motors can be picked up for under $100. If your low on cash I'd pick up a everstart size 24 deep cycle battery. I've gotten about 2-3 years use out of those batteries. We've found that anything bigger than a 40 lb thrust with a 2 blade prop to be slower than the smaller motors.

 

[Silvertip]

Re: Thrust needed for small boat?

Physics is being turned back a couple hundred years here. Jeez Louise!

 

[John_S]

Re: Thrust needed for small boat?

Physics is being turned back a couple hundred years here. Jeez Louise!

That's because the 40+lb thrust cavitates behind the shaft.