Outboard Engines

Outboard size and how it is steered:

the small portables, up to around 20 hp, are tiller engines that one or two people can lift off the transom and carry to a car. They push tenders, inflatables and small aluminium or wooden boats, and paired with a boat from dinghies one makes a package that fits in the bed of a pickup. From the mid-range up, an engine is either tiller-steered, which suits a working panga, or rigged for remote steering with a wheel, cables and a control box at a console. At the top sit the big four-strokes on sportfishing and family boats, always remote-controlled and often in pairs; inboards and sterndrives sit one level up under boat engines. Electric outboards from Torqeedo or ePropulsion are silent and light enough for a kayak or a sailboat tender, but the battery keeps them to short trips.

Matching the shaft to the transom:

an outboard should sit with its anti-ventilation plate level with the bottom of the hull, so shaft length has to suit the height of the transom. Short, long and extra-long are the usual steps, and the model code often gives it away: on many Yamaha engines an S at the end means short and an L long. Too short and the propeller sucks air and slips; too long and the leg drags and throws spray. Two-strokes split into simple carburetted engines that run on premix or an oil-injection tank, and direct-injection ones such as Mercury’s OptiMax or Evinrude’s E-TEC, which burn cleaner but need a workshop with the right diagnostic software.

Yamaha look-alikes and the badge on the cowling:

parts and service follow the agency, so find out whether the brand has a workshop within reach of where the boat lives, which from Sámara or Paquera can mean a long drive. Several Chinese makers, Hidea among them, build small and mid-range engines on Yamaha-style mechanicals under their own names. They are legitimate and cheaper, but resell for less, and some parts that look identical are not. The trouble starts when a listing presents one as a Yamaha, or an old engine wears fresh decals: the model code and serial number on the bracket label should match the name on the cover.

What the telltale and the tilt tube tell you:

ask to see the engine run in the water rather than on flushing muffs, and watch the telltale, the thin jet of cooling water at the back. A steady stream shows water is moving, although a worn impeller can still make a decent-looking stream while cooling too little under load; impellers and pump kits are listed under boat engine parts. Lift the cowling and look for blistered or browned paint on the cylinder head, a sign of overheating. Tilt the engine all the way up and down: a tilt tube and clamp brackets seized with salt make every launch a fight, and power trim that sags overnight or weeps fluid needs seals. Ask for the purchase invoice or other paperwork, and walk away from an engine whose serial number has been scratched or ground off.

Photos, papers and the side it travels on:

outboards come up for sale when an owner moves to more power, sells the hull but keeps the engine, or gives up boating. Put horsepower, two-stroke or four-stroke, shaft length and tiller or remote in the title, then list what goes with it: tank and fuel line, propeller, key, controls and harness. Film it starting with the telltale in shot and running in forward and reverse, and say when the impeller and gear oil were last changed. A four-stroke has to travel upright on a stand or lying on the side its manual allows, so a buyer driving down from San Ramón with a hatchback needs to hear which side that is before loading it.