Any of you folks run long shaft motors on a standard transom?

[KDewees91]

Got a long shaft motor and didn't know if I'd run into any problems or not with this.

-KD

 

[MH Hawker]

Re: Any of you folks run long shaft motors on a standard transom?

you can but it will run a bit slower due to the drag from the extra depth.

 

[Mel Taylor]

Re: Any of you folks run long shaft motors on a standard transom?

It depends on the boat. I've run a long shaft, 25 horse, motor on at least three short transom, tiller steered, 14 and 15 ft. v hull tinnies at different times with no discernible difference in performance from a short shaft motor except the steering was a little squirrelly on the boat with the shallowest hull. By that, I mean you had to be a little more cautious when turning. If you turned too sharply the boat tended to list toward the side on the inside of the turn. That could have been dangerous in the hands of someone inexperienced or stupid enough to play dare devil.

I'd say try it and see how it works. Just be careful until you know how it handles. I'm sure others on this forum will have differing opinions.

 

[ssobol]

Re: Any of you folks run long shaft motors on a standard transom?

Got a long shaft motor and didn't know if I'd run into any problems or not with this.

-KD

I had a Zodiac RIB that had a long shaft motor on it when it should have had a short shaft. The motor was mounted as high as it could go (based on the transom shape and the hole pattern). There was a gap of about 3 inches between the top of the transom and the part of the motor mount that normally hooks over the top of the transom.

The boat ran and handled fine. The only issues were that it could tend to push the bow up quite high when accelerating (e.g. hole shot) because the thrust moment arm of the motor was longer (once it planed it rode fine). If the motor was trimmed out a bit and the boat aft loaded you could get in a situation with the nose way up, the engine at high power, and not be able to accelerate onto the plane (this might not be due to the long shaft motor though).

There was also the issue of greater splashing around the transom. The average motor shaft has a fairly wide profile down to the anti ventilation plate where it gets a much finer edge. Since normally the anti ventilation plate is just at the surface of the water the thicker part of the shaft is not submerged. If this part of the shaft is in the water you'll have higher drag and a lot of spray going to both sides of the engine. If you have a hard boat this may just end up on your swim step. In the case of my Zodiac I ended with water spraying on to both tube ends (but this wasn't really a problem).

You can buy jack plates and mounts that will raise the motor to the proper height. I made some myself to raise my motor, but sold the boat before I installed them so I don't know how the handling would have changed.