All systems go

Finally, I had almost restored my Sea Nymph Commander after it sank on a rocky beach. After fitting a motor and control systems I faced the ultimate test: a sea trial. At first everything seemed fine…

Iput a lot of thought into the selection of my outboard motor. At the time, about four years ago, four-strokes were all the rage, and Yamaha led the sales by a good margin but I couldn’t get the horsepower I needed at the weight I wanted. The modern fourstrokes were way too heavy for my old-style, 20-inch transom and didn’t have the torque to push a 19ft boat that weighs 1,250kg unladen.

Lighter four-strokes are now available, and if I was buying today I might decide differently, but in the end I went for a secondhand 150hp Evinrude E-tec. It was a V6 like my previous fuel-and-oil-thirsty 135hp Mariner and weighed only 12kg more, so I knew the weight would be about right. As for torque, being a two-stroke, it would have a lot more push than anything near that horsepower in the four-stroke range.

I had heard the claims on the four-stroke vs two-stroke debate, and mostly they made sense. The four-strokes are quieter at idle and use less fuel, but the two-strokes require less servicing. However, I struggled with the claim that the two-stroke E-tecs have lower emissions than any other outboard, including the four-strokes.

If, like me, you grew up with the early model outboards and owned several oil-mixing systems over the years, it was hard to accept that a two-stroke could have lower emissions than a fourstroke. How could something that burns its oil compete with a wet sump-style motor like a four-stroke?

Once I got the motor set up I was surprised at how little smoke it produced. There was basically no visible smoke at any stage of operation, including start-up when even the latest four-strokes tend to give a little puff as the auto choke comes into play.

The E-tec scores its points for low emissions because it produces very little carbon monoxide. This is one of the nastiest emissions: invisible, odourless and poisonous.

My next step was to mount the E-tec on the transom. I planned to do the work myself and then take the rig to Outboard Marine Technologies to check my work and set up the steering and gauges.

To lift the engine to transom height, I copied a factory-designed lifting shackle I had seen at Outboard Marine Technologies and made one myself in about an hour. It was worth it as I would use it several times.

I also bought a set of trim wedges from Trademe to get more negative trim; that is, the motor trims up under the back of the boat so that, when you apply the power from a standing start, the boat is lifted as well as driven forward. This gets you on the plane faster, although, thanks to the sheer power of the E-tec I am not sure that I needed the wedges, but they would have made all the difference if I had gone for one of the smaller horsepower, and therefore lighter, four-strokes.

Next I purchased the right length 316 stainless bolts with Nyloc nuts from Anzor and made a set of extra-heavy washers out of stainless. I would need a long series drill of the right size to match

the bolts so I made one by extending a normal drill with a piece of steel rod brazed on. Lastly, I bought a tube of Sika 291 polyurethane.

I lifted the motor on an overhead workshop crane, although it could be done with an engine lifter or a fork-hoist. Even a block and tackle at home would do the trick if you moved the boat on its trailer to position the transom correctly relative to the outboard.

Before I clamped the motor in position to drill the holes for mounting, I had marked the position with pencil and tape. Then I aligned the motor with the pencil marks, and double checked and eyeballed it before drilling through the transom from the back. This meant the holes on the motor guided the drill and as long as the motor was in the right place, according to the pencil marks, the holes would be, too.

There is one trick: which set of holes to drill through on the outboard bracket. Most motors have four or five options, or a slot. The normal approach is to set the motor to about the right height and then go through a middle hole, or one hole up from the middle. That way there is scope to lift or lower the motor depending on how it performs. Don’t go through a hole at either the top or bottom, as you will be limited to adjustment in only one direction; ie, if you drill the top hole you won’t be able to lower the motor and vice versa.

Beyond the actual positioning, the most time-consuming part of mounting a motor neatly is the sealant job. This needs to be done well, to look good and to keep water out of places it can do damage.

To stop corrosion, use sealant anywhere that can trap water; for example, unused mounting holes mentioned above. If you don’t fill them with sealant they will remain damp and corrosion will begin there. It will spread from that point outwards, wicking out of the corroded hole.

Having fitted the motor, I mounted the gauges in the dash and put the wiring loom in place. Like many modern motors, the wiring in the E-tec is based on a Canbus network. They are easy to install as there is only one wire running front to back and

“Don’t go through a hole at either the top or bottom, as you will be limited to adjustment in only direction...“

important as you want it to fall to hand easily – especially in a rough sea. I moved mine around a few times which meant a couple of extra holes behind the remote box. I cut off a couple of countersunk 316 screws and Urethaned them in to seal them up.

I took the boat and outboard to Outboard Marine for the guys to check my work and finish the job. They installed the hydraulic steering and set up the fuel tank gauge, calibrated other gauges and gave the engine a test-run in their tank. They added a second charging loop for the additional battery and made sure I had the right fuel clips and that cabling was clamped and tied properly. I was ready for a sea trial. Normally I launch out of Half Moon Bay but for the first run I decided to go to Westmere where it was calmer and there was more assistance available should I have trouble. I had been so