# thrust size ?



## kully560 (Feb 20, 2019)

I have a 1987 gamefisher tin boat with a v hull and a 16 " transom. what size trolling motor should I buy and shaft length ? I am looking at a minn kota 40- 45lb 12v motor with a 36" shaft is this going to be enought motor? I will fish with 2 people on board 95% of the time. thanks for the help


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## gnappi (Feb 20, 2019)

kully560 said:


> I have a 1987 gamefisher tin boat with a v hull and a 16 " transom. what size trolling motor should I buy and shaft length ? I am looking at a minn kota 40- 45lb 12v motor with a 36" shaft is this going to be enought motor? I will fish with 2 people on board 95% of the time. thanks for the help



I can't see a penalty (except price) for having the larger TM (or even bigger) especially If / when you have a full boat and a stiff wind to deal with, or you find yourself in thick weeds (I use a Kipewa 3 blade prop for heavy weed chopping) IMO. 

My little Lowe 1040 (15" transom) has a 50 lb / 36" shaft on the back and it's literally off the recommended selection chart but I have yet to regret selecting it. Even in heavy wind with full gear, a second passenger and thick weeds (not impassible weeds) it has yet to disappoint me. 

As far as the motor you're looking at goes... if you place lots of importance on the charts you will have to give more info than you have given here. LOA, expected weight etc. Look here:

https://www.westmarine.com/WestAdvisor/Get-the-Right-Size-Trolling-Motor


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## kully560 (Feb 20, 2019)

hi gary thanks for the reply . I am looking at the minn kota endura max 40-45lb, they do make up to 55lb for a single 12v battery. just would like to have enough power for a full with max weight of 1500 lbs total . minn kota charts say 30lbs but I do not think that is enough. so I was going to up the lbs to 40-45lbs .one rep at minn kota told me yesterday that bigger is all ways better an suggest a 55lbs tm . today another rep suggest a 40lb. tm sop as not to kill the battery for a day of fishing.


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## gnappi (Feb 20, 2019)

kully560 said:


> >>SNIP<<today another rep suggest a 40lb. tm sop as not to kill the battery for a day of fishing.



First off, are you running all electric? Or, do you spend most of the day using the TM or a lot of casting dead in the water? Alot depends on how you use the TM.

Anyway, I've read that *larger* thrust motors at slower settings (which I bet most use most of the time) actually use *LESS* current than a lower rated thrust motor at the same speed / amount of thrust applied.

That said, my 50 lb TM on my all electric boat and I will get four + hours run time (drained to 11.9 volts or 40% DOD) on a single tiny 35Ah solar / wheel chair battery, and I have three. The second is spare in case I run over 4 hours on the first, in the event I run over 8 hours which is very doubtful I can use the third "house" battery as my spare tank. I'm also conservative on the DOD even though my batteries are deep cycle and could drain them down further.

When I got my boat, I could (and did) run my boat all day on my Waaayyy too big and heavy 92Ah battery with power left to spare at the dock. Considering I'm running all electric, I seriously doubt run time will be an issue with the 55lb. the first sales man recommended.

Obviously some of this depends on your boat configuration. If you're running a gas motor and need to lots of starts on it with one battery for it and the TM, and the age / Ah rating of a single battery, or if you're running second separate TM battery and or a house battery.

Food for thought...

I setup a "house" battery for my DF, lights, and electronics because goosing the TM would drop the DC on the TM battery enough to reset the DF and GPS. A house battery fixed that. 

I'm running THREE 35Ah batteries for a total of 105 Ah at ~65 lbs and they're easier to distribute weight, and it gives me backup should one battery fail. My old setup was a 92 Ah TM battery AND a single 35Ah house battery and weighed 85 pounds. 

I'm on season three with this setup and it's worked out very well, the last thing I think about is TM / battery issues.


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## kully560 (Feb 20, 2019)

no electric on the boat, and the gas motor is manual start. I just need the tm motor for the lakes that require no gas motors , and for a backup if the old gas motor quits . also maybe a fish finder I will run but that is it . the reason I ask is I read on line that the minn kota endura max 55lb is power hungry but I have no way of checking that that's why I was asking on this forum.


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## gnappi (Feb 20, 2019)

kully560 said:


> no electric on the boat, and the gas motor is manual start. I just need the tm motor for the lakes that require no gas motors , and for a backup if the old gas motor quits . also maybe a fish finder I will run but that is it . the reason I ask is I read on line that the minn kota endura max 55lb is power hungry but I have no way of checking that that's why I was asking on this forum.



Dunno about the 55 but I can attest to the fact that my Endura C2 50 even if bogged down cutting weeds has never tripped the 45A breakers I installed. I installed deliberately on the low side as my cable run is only 3 feet, and because I can switch immediately to a second battery if needed. I have yet to setup a current meter for the 5 throttle settings but I may some day. 

Minn Kota recommends: 50 lb., 55 lb. thrust--- Max amp draw 50A Circuit breaker 60 Amp @ 12 VDC


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## New River Rat (Feb 21, 2019)

Kully, I fish the New River here in VA and the MK 55 has been a staple on my tins since they started making them. Almost enough power to combat the current. I run 29 series batteries in parallel. This battery bank increases the amps but allows the voltage to stay the same. My amp hours are doubled.

Oh yeah, the reason for the MK 55 was simple. Highest pound thrust on a 12v trolling motor. Better to have it and not need it than need it and not have it.


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## Wallyc (Feb 21, 2019)

I would run a55 lb thrust endura max .i can tell you from 30 yrs of experience I would not go any smaller . I run electric only. I’was pushing at the time a 1448 weld built fully loaded. Now a 1648 grizzly. 45lb will work until you get into a 25mph wind and it has trouble keeping up . Something else to think about with the max model you get the maximizer that extends battery life “time on the water”. One last thing you can never have too much motor but you can definitely not have enough. Good luck and tight lines!


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## kully560 (Feb 21, 2019)

thanks ever body for the help I will get the 55lb endura max


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