We’ve had a 30 HP Yamaha outboard on our dinghies going back to the days of Sundeer. Our first 30 was with us for 15+ years, and went to a new home when we sold Beowulf.

It was a great engine, giving us excellent service, so when the time came to pick an outboard for Wind Horse we went back to the same engine. Most of the time we use 20% of the power. Those 30 horse only come into play when we water ski.

Our maintenance schedule has been pretty simple. Keep the engine clean, give it an occasional spray with a water-displacing lubricant like WD40 or CRC, grease the four Zirc fittings, and change the spark plugs and lower unit oil once a year.

On Wind Horse‘s dink we went to a steering wheel with remote shift/throttle to ease handling (we have always used a tiller in the past), so this introduced some new maintenance issues, some of which we were not previously aware of. Rather than connect the steering wheel with cable and blocks as we were used to, a push/pull rod was used (it is simpler, in theory at least, and gives more positive control). Living in salt water, the rod requires periodic maintenance. However, the only way to properly lube the rod is to remove it from the engine, clean, and then grease it. Easy to do if you are ahead of the maintenance curve. If you fall behind…well, that is what prompted this article.

The outboard has now been aboard for 16,000 miles and 15 months. Prior to the last month or two, the steering worked fine, albeit a little stiffly. Then it froze. We applied some pressure, lubed various pieces, even tapped gently with our shot-filled mallet, all to no avail.

Since we were in Ventura, CA, we called Inflatable Boat Specialists ( www.inflatableboatshop.com ), the local Yamaha dealer. Coincidentally this is where, many years ago, we bought our first 30. Dave Eagan is their mechanic (he’s been at this 26 years). Using a bit of heat from a small propane torch, directed at the center of the control rod where it runs through the outboard, a hammer, and block of wood, he had the rod free of the outboard. We wanted to get photos of this process but it happened so fast we missed out. (Dave cautions, if you do this yourself, take care not to ignite the gasoline fuel line!)

Although the engine has very few hours on it, we decided to have Dave go through the maintenance procedure with us, so we don’t miss anything in the future. His comments apply to almost all outboards. At the end we’ll touch on the steering lube process, in case you have remote steering.

The first thing to check is the cooling water. There should be a strong, steady stream coming out (and periodically check this when using the outboard). If the stream is not full strength, there are three areas to investigate.

The first is the cooling water intake screen on the lower unit, near the propeller. If this is blocked by debris, it will reduce water flow.

If the intake is clean, the next possibility is the engine thermostat. Ours is mounted on the top of the block, at the aft end. Find out where yours is. These are subject to salt build up and then don’t open properly. Carry a spare.

If the intake is OK and the thermostat is not blocked, this leaves the water pump impeller. It is located in the lower unit, requiring disassembly. We’ve twice had these go bad, and used our spares and the services of a local mechanic to deal with the replacement.

Engines that are run in salt water tend to build up salt debris in their cooling passages over time. So it is a good idea to flush the lower unit periodically. This is easily done with a “muff” as shown above (which you can purchase in most marine stores). The muff is placed over the water intake, and then a moderate amount of fresh water pressure is applied. Once the water is flowing, the engine is started and run for five minutes.

When we asked Dave how often this should be done; like most mechanics, his first answer was as often as possible. When we indicated that the schedule was likely to be less often than he would like, he indicated at a minimum each time the engine is laid up for any period of time.

Dave Eagan suggests that the oil be changed in the lower unit once a year, even with low usage. The oil itself is probably OK, but changing it is a chance to check the condition of the shaft seal. If this starts leaking, and you have water mixed with oil sitting in your lower unit, it gets expensive in a hurry.

There will be two plugs on the lower unit. The upper for filling and bleeding, and the lower for draining.

This is our lower plug. Note the gasket – which should be replaced with each oil change – and the debris on the magnet tip. Magnetic drain plugs are pretty common on today’s engines, and this is a normal amount of debris for a new engine.

There will be some condensation of moisture in the lower unit. This combines with the oil and looks like the photo above. Dave says this is normal. If the shaft seal were leaking there would be more moisture and the oil would be frothy and whiter in color. If you see the froth and whiter oil/water mixture, it is a sign to check the lower unit and shaft seals.

To replace oil, use a pump or one of the squeeze tubes of lower unit oil (usually 90 weight) and force the oil from the bottom plug into the lower unit until a clear flow runs out of the upper plug. Replace gaskets on plugs, and then insert and tighten upper plug. Then remove squeeze tube or pump hose from lower opening and replace fill plug.

Although there are very few hours on this engine – we’ve run about 30 gallons (120 liters) of fuel through it since new – we decided to have Dave check the plugs. This photo shows what a clean running engine should look like – almost no deposits of carbon. The plugs were a little damp as the engine had been idled across the harbor. Dave said that spark plugs now come with their gaps preset. But he suggests checking them anyway with a feeler gauge.

Each engine has an internal fuel filter. This needs to be checked for debris and water. Ours is clean, as you can see above. At Dave’s suggestion we are going to add a larger pre-filter to the fuel line from the plastic tank.

The inside of the engine looked clean and dry, an indicator that engine cover seals are working well (the engine sits exposed on the dinghy, with no extra cover). We give this a spray of CRC once a month.

That’s about it, except for our previously mentioned Zirc grease fittings…

…which we lube every couple of months (there are five).

We also greased the exposed ends of the shift/throttle control cables.

Speaking of the shift/throttle and steering controls, Dave says the most typical failure mode, other than lack of lube, is from sun damage. He says to keep an eye on the covers. When they start to break down from the UV, change them.

Which brings us to the steering rod. After removal of the rod – which is easy if you stay ahead of the lube schedule –

the first step is to clean the outside of the rod, and the inside of the outboard housing.

Dave is spraying some carb cleaner – brake cleaner will work too – into this area.

Using a long screwdriver or small diameter rod, a rag is then run back and forth to clean out the old grease. This process is repeated several times from both sides.

Dave then coats a somewhat larger diameter rod with grease and runs this back and forth in the housing, liberally coating the inside.

Grease will accumulate at both ends. The excess will be cleaned off at the end of the process.

The steering control rod is then coated and worked in. This has a tight tolerance, so it takes a bit of force to shove it through and displace the excess grease. Dave inserted and withdrew the steering rod four or five times until it slid smoothly through.

The steering is now fingertip-light.

We’ll go to steering maintenance mode in the future at the end of each cruising season, and any time the helm begins to feel the least bit tight.