4 Stroke outboard engine oil change.

4 stroke outboard engines need their oil changed. Unlike your old previous 2 stroke engines with an oil and petrol mixture, these newer 4 strokes need new oil at regular intervals. If you have a small outboard, say up to 4 horse power, then you should change the oil every 50 hours of running. For larger outboards you could go to 100 hours of running before changing the oil. If you don’t record how many hours your outboard has run, then change the oil at least once every year! New oil is needed by your outboard because the old oil degrades during engine use as it heats up and due to wear between the metals it collects metallic impurities and carbon from the combustion residue. Thats when it turns black! So change it and this will keep your outboard running longer and better efficient!

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Outboard motor security

With the summer season fast approaching boaters are not the only ones benefiting from their boats! Thieves will be out and about! Recent thefts from boats with outboard motors around the Essex coast have resulted in local police issuing a special security cover to replace your existing cowling.

Outboard motor security covers are now available for owners who can use the device to replace the outboard cowling when their boat is not in use, making it less attractive to potential thieves.
“For just £11 or £12, boat owners can help prevent the theft of an item which would cost them £200 to replace.

“At the same time, an engine with a police-branded cover is of no use to a thief who would need to go to the extra effort and cost of paying for a replacement before off-loading it.”

The PVC cover, which is manufactured by Thornham-based Nelson County Marine Covers, is available in two sizes, has breather holes to combat condensation and is designed to keep the weather out even on a wet mooring.

A chord and lockable buckle strap, which can be secured with a padlock, stop it being blown away or tampered with.

Police bring their new outboard motor security covers to Brancaster Staithe. Pictured with the cover is harbour master Mervyn Nudds and PCSO Carole Leathersich, with Nicholas Healing, of Thornham-based Nelson County Marine Covers, on the water.
Picture: ALAN MILLER 09AM05219 www.photostoday.co.uk
police-outboard-cover1

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BRIEF HISTORY OF OUTBOARD MOTOR

The first outboard motor was made by Ole Evinrude, a Norwegian-American, in 1909.

Until recently, most outboard motors were two strokes.  These engines were fitted with a carburettor and the design was fairly straight forward and simple. Nowadays, with all the emphasis on reducing pollution, two strokes are considered too heavy on unburnt hydrocarbons for todays’ world.

During the mid 1990s European directives and US exhaust emission laws made manufacturers change from two to four stroke engines. All the main marine outboard engine companies have now developed new four-stroke motors.  Most of these new engines are fuel injected apart from the smaller outboards, which still use carburettors.   Some models benefit from variable camshaft timing, and multiple valves per cylinder. Mercury Verado four-strokes are unique in that they are supercharged.

Mercury outboard motors have an interesting history.  They were started by an engineer, Carl Kiekhaefer, who sold them at first, by mail order.  The outboards were so well made- they withstood extreme conditions better than any other motors – buyers soon were purchasing massive quanities.  Nowadays, Mercury also produce Mariner outboards (outside the USA).

Mercury, Tohatsu, Yamaha and Evinrude each developed computer-controlled Direct-Injected two-stroke engines. Each brand boasts a different method of DI. Fuel economy on both direct injected and four-stroke outboards has been vastly improved.

Evinrude, founded by the inventor of the outboard motor, are a major name in the marine industry.  They became connected to Johnson outboards when they were bought by Outboard Marine Corporation (OMC).  Now both are owned by Bombardier Recreational Products.  When both these major names were acquired, their technology was updated and E-Tec direct fuel injection was introduced.  They were the first to win the American EPA 2005 Clean Air Excellence Award, which recognises low emission levels from outboard engines. The EU now also recognises this as well.
 
Honda first produced outboards in 1964. They have been making four-stroke engines ever since.
 
Suzuki started making outboards in 1965 as an extention to their cars and motorcycles.

 

British Seagull outboards were produced from the 1930s until the 1990s.  The previously mentioned exhaust emission regulations put them out of business, as a manufacturer.  However, the company still operates as a replacement parts business.  Which is just as well, for these engines go on for ever and ever.  Even the original ones made in the 1930s are still going! They are a strange outboard motor.  The models are all named after the power in pounds per thrust that they produce.  For example, the smallest, called the ‘forty minus’ gives out just less than 40pounds of thrust.  This particular outboard – just to confuse you – is also called the ‘featherweight’.  The largest engine, the ‘silver century plus’ produces over 125 pounds of thrust. Although pretty primative looking these outboards can push a fairly heavy displacement boat of, say 25 feet long.
 
This gives you a brief look into the history of outboards.  A considerable amount more could be included but this gives you an overview of the main companies.

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Maintaining your outboard motor, cheaply of course!

Every outboard motor needs maintenance.  As a bare minimum you should service your outboard engine at the start of the season. You can probably do this servicing yourself, but if you prefer it can be done by a marine mechanic.  Remember, there are no hard shoulders out at sea, so you will depend on the outboard to get you back in, safely.  So it is important you must service the outboard!

Once the outboard engine has had its annual service you can do some tasks throughout the season to keep it in tip top condition.  If you can get into the routine of flushing the outboard after every use with freshwater, to clean the internal water ways, it will help prevent corrosion and clogging.  An easy to use piece of kit, called a flushing kit, is used to connect to a water hose and also to the water intake of the outboard.  If you run the engine in neutral for a few minutes it will clear any salt water, sand or grit in the engine cooling system.  Also check that as you are pumping water into the engine, that water is leaving via the exhaust!  This should be a constant stream of warm, not hot, water.

If you are not getting a constant stream then the cooling channels may be blocked, slightly.  You can use some thin wire to insert into the exit pipe and try to clear it.  If that does not produce the required flow then you may need a new water pump. 

When you have finished flushing the outboard motor, disconnect the fuel pipe or switch off the fuel;  this is to allow the remaining fuel to be used by the engine. Check all round the engine with the cowling off and see if there are any fuel or water leaks. Repair if you can or take to your marine mechanic. If everything is OK then spray the whole engine with either WD40 or Quick-Lube.  Make sure all moving parts are sprayed and they move easily.  Close the fuel vent tap.

If you keep you outboard on the boat rail between trips then buy or make a cover to protect the engine from the weather.

 

Has your outboard gone under water?
 
What you should do if your outboard engine goes under the water?  As quickly as possible, wash the outboard with freshwater all over, to get rid of  any saltwater. Saltwater in the engine will corrode the internal parts very quickly.  Then empty all fuel from the tank and fuel lines etc.  Take out the spark plugs and either clean and dry or replace them.  Look over the engine to see if there has been any grit or sand ingested.  Try and remove it or get the engine serviced.  If there is no grit or sand then you can begin to turn the engine over, by hand.  Crank it slowly by hand, this allows water to be expelled.  Try cranking it at different angles, even upside down. To ensure all the water has drained out.

Once you are sure you have no water in the engine you can flush the cylinders and crankcase with pure alcohol, this will absorb any remaining water droplets in the engine.  If you wash all the parts in hot soapy water and allow them to dry or use a hair dryer then you will need to coat them with oil, to protect them from rusting.  Assemble the engine, add the fuel and turn over the engine.  Try starting it, if it fires up then allow it to run with some throttle in a container filled with freshwater to allow the engine to cool as it should.. The outboard motor is now ready for use.

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Choosing an outboard motor for your dinghy

30 years ago American manufacturers dominated the outboard motor market.Names such as Mercury, Johnson, Evinrude and Chrysler, led the field competing with each other to produce bigger and better outboard engines. However, while this was going on they were neglecting the smallest of the outboards. These are the outboard motors that sell in the greatest of numbers and are often the first outboard many of us, buy. This being the case many of us stick to the same brand (brand loyalty) as we buy other bigger outboards over the years. The Japanese seized on this fact and gradually Honda, Yamaha, Suzuki and Tohatsu concentrating on small outboards began to take over as market leaders. They achieved this domination by improving efficiency and reliability. As well as adding features to these small outboards previously only found on larger engines.

Having achieved success in the small outboard market, these Japanese manufacturers expanded up the power range. They again came to dominate the outboard engine market up to at least 20 hp. The American manufacturers instead of competing with the Japanese, gave up and decided to buy these engines from the Japanese and badge them as their own. Now the Chinese have entered the market. Basically doing what the Japanese did previously, copying the best features of the present engines and at the same time keeping costs down.

So let us compare the outboards that are on offer for those looking for an outboard motor for their dinghy. If we take a fairly larger dinghy say, a Pioner 12 (pictured below) so that each outboard has to push a reasonably heavy weight through the water.
 
If we then take the following outboard motors :-
Mercury 2.5hp; Mercury 3.5hp; Mariner 2.5hp; Tohatsu 3.5hp; Yamaha 2.5hp; Suzuki 2.5hp; Honda 2.3hp; and a Parsun 2.6hp. All these outboards are 4 stroke engines. This is due to an E.U. Directive that prevents 2 strokes from being sold in the E.U. These outboards will provide a fairly wide range of engines available on the market, for powering dinghies. 
 

To judge one engine against the another several tests were completed. A Bollard pull test showed that the Mercury 3.5hp and Tohatsu 3.5hp were the most powerful at 90lbs of thrust (These two engines along with the Mariner are virtually identical). The least effective was the Honda 2.3hp at 66lbs of thrust. In between were the Suzuki 2.5hp at 83lbs of thrust, the Yamaha 2.5hp at 78lbs of thrust and the Parsun 2.6hp at 70 lbs of thrust.

Next test was Fuel Consumption. At full speed – 5.75 knots, the best outboards were the Yamaha 2.5hp and the Suzuki 2.5hp by at least 20%. The worst was the Parsun 2.6hp. When the throttles were eased and the dinghy was cruising the Fuel Consumption comparision was less evident, only about 10% difference. All these figures are for 4 stroke engines. However, based on figures previously recorded for 2 strokes under similar circumstances, the older engines were up to 50% less fuel efficient at full speed. Very thirsty! Remember 2 stroke outboards are still available second hand.

Then the weight of each outboard motor was compared. Four stroke engines are heavier than older 2 strokes because of the powerhead etc. The Mercury, Mariner, Tohatsu, Yamaha and Parsun all weighed approx. 38 – 41 lbs (18 kg.). However, the Honda 2.3hp and Suzuki 2.5hp weighed a lot less at 28 lbs (12.5 kg.).

The price of each outboard motor was then compared. This was difficult to be accurate as discounts and sale offers are always changing.

Mercury 3.5hp £449

Mercury 2.5hp £380

Mariner 2.5hp £429

Tohatsu 3.5hp £449

Yamaha 2.5hp £489

Suzuki 2.5hp £379

Honda 2.3hp £429

Parsun 2.6hp £375

Although the Parsun was the cheapest and it is virtually identical the same engine as in the Yamaha 2.5hp, it is not as good. It is a bit like me following a Gordon Ramsay recipe, to the letter, but when compared side by side you just know that his food is going to be that much better. The Chinese are able to copy, just like the Japanese did before them, but they have not got it right, yet!

Finally a little about each outboard tested. The Mercury, Mariner and Tohatsu are the same engine. Starting settings for the throttle are easy to understand with the choke and stop button clearly labelled. The petrol on/off tap is not so clearly marked. All these motors have gears. Ahead and neutral then using the 360 degree rotation you can get astern thrust. There are 4 tilt positions and a shallow water ability. Oil levels can be easily checked by viewing the indicator on the side of the engine cover.

The Yamaha 2.5hp also had easily understood starting and stopping settings but the oil level gauge was out of sight under the engine casing cover. As with the Mercury outboard the Yamaha 2.5hp has gears, ahead and neutral with 360 degree rotation. Unlike the Mercury which has a shear pin, the Yamaha has a rubber hub at the propeller, so no shear pin to break.

The Suzuki 2.5hp is as above but with the oil gauge easily viewed at the side of the cover. The propeller has a shear pin with spares stowed under the engine cover.

The Honda 2.3hp is not water cooled like all the other outboards tested. It is aircooled and has no gears. Instead it uses a centrifugal clutch. This makes starting and manoeuvring more difficult than the others. It simply takes a bit of getting used to it. The oil gauge is out of sight under the cover. The propeller has a shear pin with spares kept under the engine cover.

Finally the Parsun 2.6hp, a copy of the Yamaha 2.5hp but not as good. However it is the cheapest engine when new. Fuel consumption was its biggest draw back.

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