I have a Nissan 6 HP outboard (model NSF6). There are two annoyances that I resolved.
1) The Ariel's engine mount, a block of wood, allows the engine to slide up that block and pop off it entirely. It is very unpleasant to have the engine flopping around loose under power. In reverse gear, I’ve had it fly up and nearly slap me in the face. Even though there are deep divots that have been worn into the wood by the mounting clamps, to prevent movement, the clamps still have to be torqued down so hard using tools to prevent slippage, that they eventually break. And swells pushing upward against the engine lower shaft eventually loosen the clamps and walk the engine off the wooden block regardless of how severely the clamps are tightened.
I solved this problem by installing a stainless steel bar across the top of the engine port mount. Carefully measured to allow the round clamp pads just enough clearance to pass under the bar when the engine is installed, the bar retains the engine while allowing only very slight movement, and I can install the engine and remove it (which I do after each sail) without torquing the mounts excessively. When the clamps inevitably loosen after a long sail, I only have to reach in and give the clamps another twist. The engine stays put.
2) The Nissan has a “feature” that allows the lower shaft to tilt back when the engine is in forward gear. Referring to the attached drawing, the reverse lock arm (32) engages the thrust rod (12), but only in reverse and neutral gears.
In forward gear, the engine is allowed to tilt back freely. This is a useful feature on a skiff that prevents prop damage when the skiff is run up on a beach, referred to in marketing material as a "Shallow Water Drive." But the free-tilting behavior is completely useless on a vessel where the prop is higher than the keel and will never strike the ground (you’d have to back into something to strike the prop). Plus, the tilt range in the Ariel is too limited to be of any value – only a few degrees before the engine cowl slams into the forward wall of the engine compartment (damaging the cowl).
This free-tilting behavior becomes a major annoyance when you discover that, after raising sail, your speed through the water causes the engine to tilt and force the cowl (engine cover) against the compartment wall when you select idle thrust while in forward gear, and that there is no practical way to restore the engine to vertical besides stopping the boat.
When docking, it becomes a major hazard when you try to go repeatedly from forward to reverse. If you have any forward speed, the engine will never return to a vertical position because the lower shaft is dragging through the water. As you throttle down in forward to switch gears, the engine will tilt aft. When you select reverse, the reverse lock arm can't engage because of the aft tilt, and the engine consequently slams and see-saws back and forth in the engine port.
The kind folks at Svedsen’s solved this problem for me. Referring to the attached photo, they removed the semi-circular swashplate (area marked in orange) so the push rod end (circled in red) cannot engage the reverse lock arm to move it out of the locked position. They then welded a cross piece (marked in green) to the top of the reverse lock arm. Alex in the chandlery came up with this solution. The engine now remains locked in the vertical position in all gears. The modification can be reversed by installing an original reverse lock arm.
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