While I'm happy with the performance of the 86lb thrust trolling motor I'm using, I find that I have to lower the motor so much that it makes for a pretty long lever arm to push against. It's not a problem when thrusting forward because the bottom of the motor shaft is bumping up against the lower edge of the transom near the water line. However, if I try to use full thrust in reverse, it's too much torque for the plastic motor mount to handle. I figure the solution is to clamp the motor shaft to that lower transom edge. I an idea for a quick release clamp but it involves drilling holes in that lower transom lip. Are there any problems with doing this?
Trolling Motor Mount
- Thread starter PropellerHead
- Start date
Here's what I have in mind. The red arrows show the locations of the holes I'd like to drill to support a bracket.
You are dealing with the hull to deck joint and that is not a good idea. Better think of something else and you do not want that bumping it either in forward gear if you want major leaks into the boat.
I believe the forum store sells stainless steel brackets to extend that motor mount. Suggest calling them to see and if not have some fabricated to extend that motor mount out. That will be some money well worth spent.
If there are no appropriate SS brackets as Dave suggested, maybe consider having something fabricated out of stainless by a welding shop. Consider a triangular type support that sticks say 12 to 18 inches straight out from the wood "transom" you are now using to mount the motor bracket, with a flat plate bolted to the wood. That assumes your slip or whatever can accommodate something sticking out. The hypotenuse of the triangle would be a stiff tube that goes down to just below your rear hull edge, and has some sort of clamp to attach to the leg of the trolling motor, allowing it to swivel. That clamp might be a piece of PVC tube with the right inside diameter, split and then reclamped using stainless hose clamps. It'd have to be stiff enough at the angle to provide what fore and aft support you need. Just possibly, you might even be able to fab something like that out of PVC tubes.
What about some kind of stabilizer bar that bolts to the floor of the engine well. It can extend out and capture the motor shaft. I see that the forum shop sells a motor mount that bolts to this section so I'm guessing that has the strength. I was hoping to avoid penetrating the hull but I guess this is the safer compromise?
I think it would be easy enough to test. Wedge a short 2x4 between the shaft and the transom and then push on the motor towards the transom. If I can't get the shaft to contact the transom lip then I guess I'm good to go.
Another option is to attach a short length of 2x6 to the existing motor mount in the vertical position so that it makes a kind of cross. I can then bolt the lower motor shaft bracket to the bottom of the vertical 2x6. This would transfer all the torque to the existing motor mount but it's designed for a 4hp outboard so it should be able to handle it. This would also push the motor back by the width of one 2x6 making it less likely to contact the transom lip. As I type this, I'm leaning towards this solution as it does not require any new holes in the hull.
Another option is to attach a short length of 2x6 to the existing motor mount in the vertical position so that it makes a kind of cross. I can then bolt the lower motor shaft bracket to the bottom of the vertical 2x6. This would transfer all the torque to the existing motor mount but it's designed for a 4hp outboard so it should be able to handle it. This would also push the motor back by the width of one 2x6 making it less likely to contact the transom lip. As I type this, I'm leaning towards this solution as it does not require any new holes in the hull.
PR
Check the forum sales store site to see if they have the brackets as the ones for the 240 should fit the 23.5 first to save you a bunch of headaches. Do not even think of anything bumping, the possibility of bumping or even attaching at that deck to hull lip joint; otherwise you will damage that lip not to mention a major cause of a massive water leak. That hull to deck joint is filled in with marine putty only with gel coat over it. I should know as the original plans for the 23.5 were submitted by me to Hunter when I was a dealer.
Just check first with the store. IF that is what I think they have, it is a matter of removeing four bolts, attaching those two stainless steel brackets and then rebolting the board to the bracket as they would be spaced to accept the wooden motor mount board. It is worth a try and a lot less headaches if they have them.
Check the forum sales store site to see if they have the brackets as the ones for the 240 should fit the 23.5 first to save you a bunch of headaches. Do not even think of anything bumping, the possibility of bumping or even attaching at that deck to hull lip joint; otherwise you will damage that lip not to mention a major cause of a massive water leak. That hull to deck joint is filled in with marine putty only with gel coat over it. I should know as the original plans for the 23.5 were submitted by me to Hunter when I was a dealer.
Just check first with the store. IF that is what I think they have, it is a matter of removeing four bolts, attaching those two stainless steel brackets and then rebolting the board to the bracket as they would be spaced to accept the wooden motor mount board. It is worth a try and a lot less headaches if they have them.
The problem with an off the shelf motor mount is that it doesn't replace the bracket that is integrated into the motor. It would just replace the 2x6 that's bolted to the transom now. This doesn't address the problem which is that the integrated bracket can't handle full thrust in anything but forward direction when the motor is fully extended. The designers probably didn't intend for the motor to be extended as far as I need to for this application. The only way to address this is an additional clamp on the motor shaft closer to the water line. I believe that I have a solution now that avoids contacting the deck to hull joint or drilling any new holes. I'll post pictures when it's done.
There is an old saying. Learn for those who are knowledgable and experienced. That response to me from an old friend well recognized in the sailing world as a sailor and mfg. went a long way and now in a sense I am in that position here. I know this boat better than most. I designed the boat. When the 240 replaced the 23.5, one suggestion was to extend your motor mount out away from the transom by me to Hunter and I know those brackets I spoke of were patterned after the bolt pattern of the 23.5 for the 240. In addition should you drill into the cockpit floor will devalue your boat when you sell it down the road and people will shy away from it.
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