# Trolling Motor Isolator Bolts



## RMK

looking for tips or advice from anyone who has expierence with isolator bolts used for bow mounting trolling motors. isolator bolts are the rubber coated bolts that when tightened down they expand and hold your trolling motor down tight to the deck of your boat.(when they work) i just bought 2 new sets, 8 bolts, to redo my loose trolling motor. 4 to replace the old ones and have a spare set so i would have them when they needed replaced. the new set only lasted one trip! wondering if anybody has expierenced simmilar results and if there is a better alternative to these rubber isolator bolts to hold the motor securely in place. i thought about putting a little rubber padding under the trolling motor mounting bracket and tightining it down using toggle bolts instead. ?? tired of constantly replacing the rubber isolator bolts or having a loose trolling motor. also wondered if i could be over or under tightening the isolator bolts and they arent working properly due to that.

this is on an 18ft modified v aluminum boat. bad desighn at the bow and the trolling motor dose take a real beating when going across any kind of chop on the lake.


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## Shortdrift

Never used them or had a need for them. I put a 1/8" thick rubber washer between the motor base and the deck and cinch it down. Eighty pound thrust Terrova on my Erie boat and never had to re=tighten in eight vears.


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## RMK

Shortdrift said:


> Never used them or had a need for them. I put a 1/8" thick rubber washer between the motor base and the deck and cinch it down. Eighty pound thrust Terrova on my Erie boat and never had to re=tighten in eight vears.


that would work if i could get a nut on the other end of the bolt. i cant get to the area of the end of the bolt to hold a nut tight to cinch it down. thats why an isolator bolt or something similar has to be used.


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## Seaturd

Can you give us a photo or two of what you're dealing with? It's possible correctly sized and epoxied into place Rivet Nuts might do the trick.


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## RMK

Seaturd said:


> Can you give us a photo or two of what you're dealing with? It's possible correctly sized and epoxied into place Rivet Nuts might do the trick.


i ll get some pictures tonight


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## EB1221

On my third set of rubber isolator bolts in 21 years. two different motors. So I really can't complain. Can't get at 2 of the bolts to use nuts, so that is why I went that way. Purchased from Cabelas. Rivet nut mentioned by seaturd looks good also. Same principle but may be stronger.
EB


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## bigragu

Had a similar issue. Just used the rubber bolt pads as the cushion and drilled a hole in the trolling motor bracket and sunk two stainless screws into the bow plate and tightened. No problem after that.


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## RMK

EB1221 said:


> On my third set of rubber isolator bolts in 21 years. two different motors. So I really can't complain. Can't get at 2 of the bolts to use nuts, so that is why I went that way. Purchased from Cabelas. Rivet nut mentioned by seaturd looks good also. Same principle but may be stronger.
> EB


one set every 7 years... i could handle that! it must be back to the bad design of my boat/trolling motor mount combo. i ll get some pics on here as soon as i can


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## RMK

bigragu said:


> Had a similar issue. Just used the rubber bolt pads as the cushion and drilled a hole in the trolling motor bracket and sunk two stainless screws into the bow plate and tightened. No problem after that.


thank you. thats a good idea. i ll use this as my back up plan. trying not to put any more holes in the boat. but i would definitely rather have two more holes and a sturdy trolling motor than no holes and a loose trolling motor every trip.


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## RMK

Alright.... as of this morning 4 new isolator bolts installed and then 2 new self tapping screws added in the middle.























Here is what 4 new isolator bolts looked like from half a day on the water. I say half because I changed replaced a set with these while on the water.









If the two added screws don't help I m thinking about trying something along these lines.








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I think I finally found a big part of the problem while looking at it this morning.... the holes drilled I'm the boat were either originally drilled to big or from all of the banging around the holes have wallowed out to a diameter that the isolator bolts can't expand enough to grip and hold the trolling motor tight.


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## Cajunsaugeye

Can you move up/back 1/2" or so and drill new,correct sized holes and still cover it? If you can,I'd also dremel(sand)the metal after drilling to smooth out any sharp edges and then reinstall some isolators.


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## RMK

Cajunsaugeye said:


> Can you move up/back 1/2" or so and drill new,correct sized holes and still cover it? If you can,I'd also dremel(sand)the metal after drilling to smooth out any sharp edges and then reinstall some isolators.


thank you. good idea. again more holes i dont want to put in the boat but would fix the problem.


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## Seaturd

If you've got the time this method will keep your trolling motor in place.


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## bustedrod

you could put blind nuts in maybe


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## fastwater

As Seaturd suggested, Rivet nuts, or often called 'Nutserts' would be the way I would go. Have used them many times in applications of SS, cold rolled steel, aluminum and some softer plastics.
Especially if the holes are egg shaped and you didn't want to drill additional holes. you can just drill out the existing egg shaped holes to make them round again to whatever size the dimension of the nutsert are that you are going to use.
You can buy the nutserts in most any size you want.
Here's a vid on installing them:





One thing I think I would do if using nutserts would be to take a flat piece of aluminum the thickness of the upper lip of the nutsert that will stick above the boat and cut the flat piece of aluminum to the dimensions of the trolling mtr mounting plate. After nutserts installed, take the flat plate and Mark it drawing circles a little larger than the nutserts where nutserts are at. I'd then drill the holes out in the flat plate and lay it down on boat aligning nutserts up with holes. The plate being level and flat with the tops of the nutserts will give the torque of the trolling mtr a wider area of support and would be less likely to works loose again. If you know someone that welds aluminum, you could have them spot tack the nutserts/plate to the boat for additional 'staying' strength if that made you feel better. But don't think this step would be a must.


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## RMK

thank you. those rivet nuts look strong.


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