Extra short shaft outboard

[Mark]

Down here the shortest shaft outboard is 15 inches.One of the smaller yachts I own (18') has always had an outboard hanging off the back. It needs replacing however what I would like to do is mount a new motor in a "large" stern storage box on the yacht. The idea is that either side of the leg, a section is cut out of the hull in the stern box for the leg to extend into the water so that it just protrudes from the bottom of the hull. Enough for the cavitation plate and so water inlet to be submerged of course. On each side of the hole there needs to be a glassed in wall from the hull verticle to be made well above water line. So I guess I will end up with an "inboard-outboard".My problem is trying to locate a motor with a shaft length much less than 15 inches."Help" Any ideas??

 

[Ed Allen]

not a new idea

This has been done for years, the columbia 26, and the cape dory 25 for example have done this. in the columbia you had a plug to put in the hole to use when the engine was removed. This plug had the bottom countour replicated, so the bottom of the boat remained fair.the biggest problem on the columbia was exaust fumes would back up in the hole, particulary when the engine idled. the small upper exaust vent would allow exaust to build up and the engine would starve itself for air. In the columbia the box was built amidships under the tiller, in the cape dory it was in the aft locker. Both seemed to drive the boat ok. but it is a hard task to remove the engine throught he small hole. the short shaft engine 15 inches did work but not very well the long shaft seemed to long.the columbia 26, were early 1970s mmodels. and the top of the opening was just above the floor in the back of the cockpit. this would allow the fumes to rise from the whole but settle on the floor and if open down the companionway to the cabin. the carbon monoxide displaced the air and made it very dangerous, you cant smell it. with the companionway doors in the fumes would build up especially on calm days going downwind, then the engine would starve for air and slowly stall. We had to let it sit for about 1/2 an hour to get it to run again. but it pushed the boat and stayed in the water alot better than a transom mounted engine.