Dinghy outboard motors – Doing your own maintenance! (Part 1)

Your dinghy’s outboard motor deserves as much attention and care as the main engines aboard your multihull: transferring crew in an anchorage or discovering the shoreline are things to be done in complete safety by limiting as much as possible the risk of a breakdown. Undertaking periodic engine maintenance means your outboard will be reliable and operational in the long term.

Just when you don’t need it, outboard motors can make a nuisance of themselves...

Published 26/05/2023

By Oliver Barret

Réservé aux abonnés

Issue: 190

Published: july / aug. 2023

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Even though most manufacturers are getting ready for a transition to electric, most of our tenders are still equipped with four-stroke internal combustion engines. When compared to the 2-strokes of times past, these motors are almost marvels of technology. Quieter and more sober, 4-stroke engines do however require some care and precautions to keep them working properly. What’s more, increasing prices mean you’ll want to keep them in good shape for longer. There’s nothing worse than having to paddle because the engine has stalled and won’t restart, or to hear the dealer suggest you sell your engine for parts when you were still hoping for a miracle. Careful operation and meticulous maintenance are obviously the key to the reliability and longevity of an outboard motor, that’s likely exposed to spray either on a bracket on deck or on the dinghy when it’s on the davits at the stern of your multihull. Like an inboard engine, the moving parts need both cooling and lubricating. These two points are essential to the life of your engine, but it isn’t that complicated to deal with either of these, even in the most remote anchorage, provided you have the necessary equipment of course - but that should be part of your on-board equipment anyway. On the other hand, the fuel system and electrics must also be the subject of attention. When in constant use on the transom of our dinghies, outboards are subject to large variations in temperature and humidity, which can cause damage to fuel connections and impact fuel quality. We discuss flushing, draining and electrics parts in detail. In a future issue, we’ll take a closer look at how to fix fuel feed problems and carburetor maintenance.

Philippe Bauer from Tendance Voile agreed to let us follow a full service and winterization of an 8 HP Yamaha 4-stroke outboard engine and a 5 HP Mercury with an integrated tank. Philippe tells us from the outset that engines of 10 to 15 HP and more have become so complex in terms of electronics that there is really no other alternative than to take them to a professional - and that’s better for the warranty too.

If you’re laying up for the winter - or making a long stopover in port - this is the time to deal with engine maintenance. Beware, an 8 HP 4-stroke outboard (or this rustic 18 HP 2-stroke) can already weigh getting on for 90 lbs (40 kg), so it might be useful to have an extra pair of hands. Basic maintenance should take between one and two hours... And with a little courage, let’s get on with it!

Downloading the genuine user manual is a good idea. Most maintenance guides can be easily found on the internet.

A large container or drum can be used to flush the cooling system with fresh water. Leave the engine running for 5 to 10 minutes, checking that water is discharging from the outlet. Then disconnect the fuel supply hose (located inside the cowling on a motor with an integrated tank) and wait for the engine to run out of fuel. Finally, ...

This article was published in the issue 190. To read the full article, purchase this issue or subscribe from $3/month.