Engine and Mounting

Over the months of July and August, very little work on the build has been undertaken due to other commitments and holidays, all very frustrating. This frustration was further compounded by the extraordinary difficulty experienced in purchasing an outboard motor! Chandlers within a reasonable distance from my location, either ignored my requests to submit quotes, or in the case of the eventual supplier, took my money then failed to supply the goods, resulting in me having to re-claim the funds through the credit card company. However, following almost three months of phone calls and emails I did finally managed to purchase the engine and ancillary equipment, although the whole experience soured the project to some degree.

The architect specifies a maximum engine power of 10 hp but suggests that 3 to 5 hp is sufficient for this light boat. Because of space limitations within the outboard motor well and the dimensions of the hull aperture through which the motor will project, I decide to purchase either a Honda BF 5 or a Yamaha F5, both having very similar specifications. I have previously mentioned that I intend to sail the boat around the Scottish Hebrides which are in parts subject to strong tidal streams. I therefore decided to purchase a 6 hp Yamaha F6c to deliver that little extra power; the 4, 5 and 6 hp motors in this range are all of the same external dimensions and weight so the bigger engine did not have any impact on the space considerations. I also opted for a charging coil which delivers a 12V 6A power supply to charge the battery plus a 25 litre remote fuel tank complete with delivery line to extend my operating range.

The architects design states that two hardwood blocks are to be fitted either side of the bulkhead forming the forward face of the engine well, cut on an oblique angle to achieve the correct motor trim. Before gluing I fitted the motor to make sure everything was correct but noticed that there was a degree of flexibility in the plywood bulkhead. To rectify this situation I manufactured a foot extending down to the cockpit floor and out laterally to terminate at the drainage holes. To further strengthen the joint between the block and the foot I tongued and grooved the two together, then applied an epoxy fillet at the junction between the different components and the bulkhead. I also recessed the aft engine well block and inserted two stainless steel plates to provide a wearing surface for the engine clamp face. This assembly produced an immensely strong and rigid structure.

The reinforcing foot inside the cockpit. This will be further strengthened by the abutment of

 the teak planked cockpit floor.

Stainless steel plates fitted to the wearing surface of the aft face of the hardwood block.

The Yamaha F6c sitting snug and unobtrusively in its well.