trolling motor size

jlscjs

Petty Officer 3rd Class
Joined
Dec 15, 2015
Messages
85
need to put a trolling motor on a 20ft with a 40hp, what would be a good size to use?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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47,309
with or without current
with or without wind

since your in the 'toon section, I am assuming a 'toon

problem with toons, is if there is a wind, you will need lots of power to keep it trolling where you want.

without wind and current, a little 36# thrust unit will keep you moving along for what you want.

with wind and current, a 15hp /( minimum ) kicker may be needed
 

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
Check the manufacturer web sites. They have guides to help you choose. There's a lot of variables.
 

Silvertip

Supreme Mariner
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Sep 22, 2003
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28,758
50 to 55# will work with moderate wind and/or 4mph current. Also keeps you in the 12 volt range.
 

Merc40hp

Cadet
Joined
May 19, 2013
Messages
16
My friend and I both have 18' pontoons, we both love to fish so we both installed wireless remote control motor guides, my friend chose the 12v, 55# model and I chose the 24v 75# model. Like Danforth said, wind is a factor when trolling a pontoon boat, but I've learned that dragging a 2' foot sea anchor behind your toon will cancel out any crosswind and allow you to stay on your heading and speed with ease. The real difference in the thrust and voltage of the two boats is my friend will deplete his battery in a 3/4 hours of continuous use, while I can go for a full day or longer on a single charge. Keep in mind the wind isn't always a factor, so on calm flat days, you can troll for days without recharging. And with an onboard charger, its a snap to recharge batteries over night.
 

jlscjs

Petty Officer 3rd Class
Joined
Dec 15, 2015
Messages
85
My friend and I both have 18' pontoons, we both love to fish so we both installed wireless remote control motor guides, my friend chose the 12v, 55# model and I chose the 24v 75# model. Like Danforth said, wind is a factor when trolling a pontoon boat, but I've learned that dragging a 2' foot sea anchor behind your toon will cancel out any crosswind and allow you to stay on your heading and speed with ease. The real difference in the thrust and voltage of the two boats is my friend will deplete his battery in a 3/4 hours of continuous use, while I can go for a full day or longer on a single charge. Keep in mind the wind isn't always a factor, so on calm flat days, you can troll for days without recharging. And with an onboard charger, its a snap to recharge batteries over night.

Thanks since you are using a pontoon I have another question for you, I have an older Evinrude BF2K floor mount trolling motor, I can't find any info on it but thought I would use it anyway. Since it is mounted through the floor is there anything I can do to help seal up the mounting screws so water will not get into the decking? I'm putting it over carpet so I thought I might try rubber washers on bottom of the mounting plate, I'm not crazy about using a caulk in case of removing and I don't want the caulk over the carpet. Any ideas would be much appreciated, thanks
 

NYBo

Admiral
Joined
Oct 23, 2008
Messages
7,107
Thanks since you are using a pontoon I have another question for you, I have an older Evinrude BF2K floor mount trolling motor, I can't find any info on it but thought I would use it anyway. Since it is mounted through the floor is there anything I can do to help seal up the mounting screws so water will not get into the decking? I'm putting it over carpet so I thought I might try rubber washers on bottom of the mounting plate, I'm not crazy about using a caulk in case of removing and I don't want the caulk over the carpet. Any ideas would be much appreciated, thanks

Use 3m 4200 to seal the holes. It will remain pliable enough to remove while still providing a good seal against water.
 

Merc40hp

Cadet
Joined
May 19, 2013
Messages
16
jlscjs, The BF2K is a early 1990 series motor with only 26.5 max pounds of thrust at 30 amps . Considering your mounting it on a pontoon boat which is harder to push and steer than a single hull boat, you may want to invest in a higher thrust motor otherwise any wind at all, and you'lll be going in every direction except the one you want.
 

BLT2

Recruit
Joined
Feb 24, 2018
Messages
1
My friend and I both have 18' pontoons, we both love to fish so we both installed wireless remote control motor guides, my friend chose the 12v, 55# model and I chose the 24v 75# model. Like Danforth said, wind is a factor when trolling a pontoon boat, but I've learned that dragging a 2' foot sea anchor behind your toon will cancel out any crosswind and allow you to stay on your heading and speed with ease. The real difference in the thrust and voltage of the two boats is my friend will deplete his battery in a 3/4 hours of continuous use, while I can go for a full day or longer on a single charge. Keep in mind the wind isn't always a factor, so on calm flat days, you can troll for days without recharging. And with an onboard charger, its a snap to recharge batteries over night.

Is The 2 foot sea anchor one of those parachute type anchors?
 

lmuss53

Lieutenant Junior Grade
Joined
Sep 9, 2008
Messages
1,227
I've had a 55# Minnkota pontoon model on 2 or three pontoons from 19 to 24 feet, with a good group 29 battery it is good for a whole day of stump hopping or slow trolling for stripers.

I've had Minnkota PowerGuide models with auto pilot, co pilot and now i pilot set ups, on Minnkota quick slide mounts that work very well on pontoons, I usually stick to the 55# on those too, to keep it down to one battery.

I have used a tiller type 36 pound Minnkota several times and it is workable, it has to work a little harder to do the same stuff, but the end result is much the same, that would be ok for a starter I would say. I made a little right angle bracket with a piece of 4 inch aluminum angle and a length of 2x6 to mount the tiller type to the pontoon deck.

I bolt them down thru, and use a little clear silicone on the plywood end of the bolt to seal it up.
 

Lightwin 3

Petty Officer 1st Class
Joined
May 18, 2010
Messages
300
There is something to be said, on the positive side, for sticking with 12V. One battery is easier to install and store than two.

I've had both 12 and 24 V. The 12V being a MG 55# on a Boston Whaler. More than adequate.

I've also had an MK 65 24V on an 18' Alumacraft. Way more than adequate. The Alumacraft had plenty of area for storage, thus the 24V.

I think either would be adequate for a smaller pontoon for general poking around.

Another conderation is shaft length. I assume this would be mounted on the front deck? If so, pontoons can be high off of the water. The longer the shaft the better. You can adjust up a long shaft motor but you can't adjust down one that is too short. Measure twice and buy once!

I bought both of them, slightly used, on Craigslist for about 2/3 the price of new.

I did add wireless remotes to both. Please note, you can omly do this with motor driven steering. You can't do it with cable driven units. That option is definetely worthwhile.

I also installed on board chargers for both set ups. Very convenient.

Also, pay special attention to wire size and connections. The larger the gage of wire and the better the connections are, the more efficient the motors will run.
 
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