I have spent some time trying to get satisfactory performance and raising ability from the engine mount.

Firstly, I think the vertical transom mount shown on the plans is very poor and the plans should be modified. It should have been sloped to allow the engine to be at the correct angle in the water at least. I use a Mercury sail power 4 long shaft (20"). The first problem was that the engine was not deep enough in the water so at full power in anything but the calmest of water, the prop kept cavitating and the engine revs rise alarmingly. The first mod was to lower the mount as shown in the photo below. This improved, but did not solve the cavitation problem. Also the engine had to be retained in the "up" position with a bungee cord as the uplock would not engage.

The next mod was to cut out the centre of the transom mount and to reinstall it with the bottom raked forward. It was also lowered even more. The piece cut out was reaffixed by triangles of half inch ply to the original parts of the mount. (see sketch). The angle at which the cut-out is reaffixed is critical if the engine's own uplock is to be used. I assembled the centre deck and the aft beam on supports in the workshop to do this. I found that if the engine is rotated 90 degrees on its steering bearings as is raised to the uplock, it will go up a bit further. ( This also avoids kinking the fuel feed pipe if using an external tank.) The slope of the transom needs to be determined in conjunction with the engine so that the uplock will just engage as the engine leg touches the underside of the aft beam. As the lock engages, the engine will drop back a bit. After the transom mount is complete, the angle of the engine in the running position is fixed by suitable positioning of the adjustment provided on the engine. In my case, I found that I had made the tilted part of the transom too narrow to use the adjustable handle provided. So I made a new one from a piece of stainless steel rod retained by split pins.

The results are very much better and are just acceptable. In calm water the engine will give me 7 knots. However in rough water speed is still limited by cavitation problems. In a two hour punch back into wind in rough water only 2 or 3 knots could be managed. One hand had to be on the throttle all the time to control rpm. A very wearing business. In rough water when sailing, the prop is inclined to catch the tops of waves and so kicks up spray. The Mercury gives very good push both forward and in reverse. Having F-N-R gears is invaluable when manoeuvring. I am glad I did not rely on a 180 degrees rotation of the engine to provide reverse.

The Bristol Channel, where I sail, can get rough very quickly, there are strong tides and not many "bolt holes". Not to mention mooring and getting back home in time! Thus I would not consider operating without an effective and reliable engine.