good depth for trolling motor

snuffy45

Seaman Apprentice
Joined
Jul 25, 2008
Messages
41
my pontoon boat has a trolling motor that has been rigged to fit on it. when it is down the blades barely go under water,about even with the pontoon. with my son on with me he can set in front seat beside me and it pushes the blades about 2 inches under water and it will move the boat around. if I'm by myself the blades spin out of the water. I want to lower the unit so having to put extra weight in front won't be necessary. I think it will work better lower. my question: is there a depth that is to low? seems like even a few inches makes a big difference. just don't want to go to far. thanks
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: good depth for trolling motor

Wrong shaft length, Snuffy. Get a longer shaft troller.
 

Silvertip

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Sep 22, 2003
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28,758
Re: good depth for trolling motor

Any trolling motor, regardless of type or manufacturer, recommends selecting a shaft length that is equal to the distance from the bow to the water line plus one foot. In other words, you want the centerline of the prop one foot or more below the surface of the water. In your case you definitely need a longer shaft (if the motor is already as low as it can be positioned).
 

snuffy45

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Jul 25, 2008
Messages
41
Re: good depth for trolling motor

I tried to lower the unit today and can lower it about 10". but then I can't swing or lift trolling motor up out of water because it hits top rail on pontoon. only way to make that work is to cut a section out of top rail which I don't want to do. can you swap the shafts in them and if so where to find, have looked but not found anything about changing shaft. is it best for me to just buy trolling motor with longer shaft. wish I could find somewhere to trade mine for another one. thanks
 

snuffy45

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Jul 25, 2008
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41
Re: good depth for trolling motor

by the way it is a OMC COBRA. best I can tell it is 44" shaft from bottom of top housing to center of prop. model # OBFL2TA
 

John_S

Rear Admiral
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Jun 21, 2004
Messages
4,269
Re: good depth for trolling motor

Maybe the trolling motor location can be moved? Post a pic for som possible suggestions.
 

Silvertip

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Sep 22, 2003
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28,758
Re: good depth for trolling motor

I don't have a picture of the modification I made on my pontoon but here's the deal. I have a Misty Harbor 4-point fish meaning it has a fishing chair in all four corners. The bow gate had about 8 inches of clearance beneath it so a trolling motor could be stowed with the door closed. The Minnkota PD was a tad high so I had to run with the gate open but could close it when the motor was deployed for fishing. I solved the problem by cutting an 8-inch section of the bottom gate tube, then cutting that piece to fit vertically between the top and bottom tubes. This gave me the clearance I need. If the motor is stowed, I simply open the gate to deploy it, then close the gate while fishing. I reverse the process when I leave. If you don't have a bow gate, then you might consider mounting the troller at an angle. It doesn't matter how much of an angle you have as long as the shaft clears the deck. The shaft will always push forward regardless how the mount is oriented. On pontoons, motors like the Minnkota Power Drive V2 Pontoon work well.
 

snuffy45

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Joined
Jul 25, 2008
Messages
41
Re: good depth for trolling motor

trying to add pic's. hope this works. as you can see it is mounted with part of trolling motor mount from the type that flips open. thought about where the door is but wasn't sure how it would work in the center, but have to be able to close door when boat is in operation according to TWRA boating requirements. well never mind the pic's they are to big according to this site, don't know how to make them smaller kb's. ain't taking chance of messing up wife's camera trying to change settings. I've tried to shrink size no luck even with cell phone camera, can you tell I'm not electronic's expert. dumb old country boy truck driver.
 

Silvertip

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Sep 22, 2003
Messages
28,758
Re: good depth for trolling motor

Without a picture there is no way I can help any further. Your pictures need to be hosted on a web site like Photobucket.com. You upload the picture to photobucket. Copy the link and paste it in the message. I'll try and get a picture today and post it later.
 

snuffy45

Seaman Apprentice
Joined
Jul 25, 2008
Messages
41
Re: good depth for trolling motor

DSCF0946.jpg

DSCF0943.jpg

DSCF0941.jpg

thanks for the help
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: good depth for trolling motor

You are losing a gread deal of forward thrust because the prop is pushing water against the pontoon. The troller should be mounted in the center. Since your bow door is already set up for a troller, why not reconstruct the mount and mount it in the middle. You open the door to deploy the troller and then you can close it for fishing. When you want to raise the motor you open the door again, stow the motor, close the door and away you go. Makes a nice neat setup.
 

snuffy45

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Joined
Jul 25, 2008
Messages
41
Re: good depth for trolling motor

thank you for the info. I would really like it in the middle. wish I had the rest of the bracket for this one then I could fold it out to use then fold up to motor. again thanks, I will start thinking on how to mount it in middle.
 

Silvertip

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Joined
Sep 22, 2003
Messages
28,758
Re: good depth for trolling motor

Check with some of your local marine dealers. The trade in older boats all the time with bad trolling motors but the mounts are perfectly fine. You might get one cheap. Or buy the entire non-functional motor and swap yours onto the mount. Check E-bay. Check Twin Cities Outboard as they have tons of this stuff.
 
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