For a traveling sailor, a dinghy is a lifeline. We use ours everyday, whether it’s exploring a new anchorage, zipping over to the trailhead in the next bay around the headland, or ferrying groceries or other supplies from shore to the boat. It’s the cruiser equivalent of a car for land folks, and the thing that makes the dinghy go is the outboard.
Our outboard is a Tohatsu 9.8hp 4-stroke – it’s a 2004 model, so it’s now more than 20 years old. And it’s been surprisingly reliable, aside from normal maintenance requirements and a carburetor that’s a bit sensitive to fuel quality. The outboard even survived a dunking outside of Oban, Scotland, when an errant gust of wind flipped the dinghy upside down, outboard attached, while at anchor.
So when our normally reliable outboard started hesitating, smelling like gas, and vibrating strangely, it was something that definitely needed to be addressed, especially as we had friends coming for a visit. The strange behavior started only intermittently – at planing speed, the engine would periodically hesitate for a second or so before returning to its normal smooth running. Over the course of two weeks, intermittent became fairly regular, and then fairly regular became always.
We tried everything we could. The first culprit for a hesitating outboard, at least one with a slightly finicky fuel system like ours, is the carburetor. So off it came to be disassembled, cleaned, reassembled, and reinstalled. That didn’t work, so we replaced the carburetor with a new one. We changed the spark plugs, we changed the engine oil, and lower unit oil, as long as we were at it. We replaced the fuel filter on the engine, and carefully inspected the one in the fuel tank. And we even siphoned a couple of gallons of gas into a rental car so that we could start with fresh fuel.
We finally traced the problem down to the ignition coil. Our engine has one ignition coil that fires both cylinders. Somehow, despite looking virtually new on the outside without any sign of corrosion or damage, the ignition coil would fire one cylinder, but not the other.
Our friends came and went, graciously putting up with dinghy rides at less than walking pace. And two days of sailing later, from Antigua to St Barth and then on to St Martin, and then a bus ride from the French side of the island to the Dutch side, we were able to get to the chandlery that miraculously had a new ignition coil in stock.
Replacing the ignition coil is actually very easy – just three bolts to remove, a couple of electrical connections and then the wires to the spark plugs. With the new one in place, we held our breath and pulled the cord…
Success! The engine roared to life on the first pull, just like it used to. And we celebrated with a long dinghy ride, at full planing speed, to the St Maarten Yacht Club for what felt like a well-deserved drink.
