Hi Cyril, now that we own 2 Capri 30's .... One of our 30's, Alliance, came with and inboard (removed 20 years ago), the other, Wandere, came setup for outboards from the factory. On Alliance we used the West Marine, 4 stroke, 85lb capacity, lifting bracket. I cut 1.5" off the top of the nylon plate to allow our 3.5 hp motor to make enough contact with the water. Here is the thing - the capri lifts the water, fills the stern wave, as it moves forward. We actually like to adjust the bracket up a notch or two when at speed. Our PHRF group requires the boat under motor achieves a speed equal or better than the square root of the waterline length. Our MORC rating certificate had the measured waterline at 24.79, so the square of 25 is 5 knots. With the 3.5 mercury two stroke, in flat water and no breeze we gotten her to 5.6 gps speed. We do have a hyper faired hull, keel and rudder.
We have a fore and aft bulkhead in our lazerette behind the rudder head. We mount and store the outboard there with the fuel. The 3.5 hp outboard weighs in at about 35lbs and is easy to mount and retrieve from the bracket while standing in the lazerette. It is difficult and dangerous to try and afix a heavier outboard on the bracket while out on the water. Because of the angle on the transom, the distance of the cockpit to the edge of the deck, you have to extend your upper body and outboard so far out that you need serious help to keep from going in. We looked into using the main halyard only to realize that a heavy outboard can become a menacing wrecking ball with any waves. Our 8hp weighs almost three times the 3.5 so we use the the floating dock to mount the bigger outboard. The 3.5 will get ya home if wind dies but forget about motoring out a rough pass with decent seas.