Transom height?

John Robinson

John Robinson

Well-known member
I have my Cackler-snowgoose hull flipped, and I am sanding and fairing before I glass this weekend. The reason I call it a Cackler-Snowgoose is because I added 12" to the LOA, 4" to the beam and have moved the motor mount aft like a Snow Goose.

I haven't cut the transom down yet and don't have a motor yet, but I expect to get a used 35-40 hp short shaft when the time comes. Since they manufacture tens of thousands of production boats with a certain transom height I assume there is a standard height that works with most short shaft outboards, am I correct in that assumption? If so what is that height? Also, with a Snow Goose transom, is the short shaft the proper choice?
 
Go to a shop and measure a couple of the short shaft motors you are looking at using. You want the top of the cavitation plate to be 1.5 to 2 inches below the bottom of the hull.

On my 25hp nissan short shaft my transom height is 17.5 inches, which I think is 2 or more inches taller than what was in the plans for my BB3. A slightly larger 40hp motor may use the same saft and mount unit but a larger power head so this distance may still be in the ball park.
 
No, unfortunately they vary. A yamaha is 17" (I think). Build it high and cut it to height once you have the motor.
 
I wouldn't do the short shaft thing. The boat calls for a 40 hp, and if you desire safety in big water you'll want a 40. A 40+ limits your shaft length choices. I believe that the only motor that I could find was a 40 Yammy. The balance were all 20" shaft.

The only advantage that a short shaft provides is a lower profile because the rig below the water line is the same as a long shaft.

Good luck. A>
 
I wouldn't do the short shaft thing. The boat calls for a 40 hp, and if you desire safety in big water you'll want a 40. A 40+ limits your shaft length choices. I believe that the only motor that I could find was a 40 Yammy. The balance were all 20" shaft.

The only advantage that a short shaft provides is a lower profile because the rig below the water line is the same as a long shaft.

Good luck. A>
Click to expand...

I agree and would go with a long shaft. A higher transom will be safer.
 
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