Outboard Motor

Laing's Outboards Newsletter January 2003
Outboard Motor | Wednesday, 20 August 2008

The debate continues on the 2 stroke vs. 4 stroke issue. After initial gains in popularity for the 4 stroke engines, the 2 strokes have been fighting back. The advantages of a 4 stroke outboard have always been low pollution, quiet smoke free operation, increased fuel economy and good low speed operating characteristics. The new generation of 2 strokes though are quickly catching up, and sometimes surpassing the 4 strokes, especially the new V-6 direct fuel injection 2 strokes. In a recent boat test, a 25 foot center console was powered by twin 225 HP outboards, one being a 4 stroke V-6, and the other being a DFI 2 stroke V-6. At wide open throttle, both engines were propped to turn about 5500 RPM at a little over 50 MPH. Then the boat was stopped and the 4 stroke was tilted out of the water. The 2-stroke DFI was opened up and planed the boat easily by itself, reaching a speed in the high 30's at about 4800 RPM. The test was repeated with the 2 stroke out of the water and the 4 stroke pushing by itself. The 4 stroke could not plane the boat. Then the two stroke was put back in the water and the 4 stroke was left in the water but shut down. The 2 stroke again planed the boat easily and still reached the high 30's, even while dragging the 4 stroke through the water. That dramatically demonstrated the low-end torque advantage of the two-stroke.

There is another factor which will soon becoming into play. It has to do with the horsepower ratings shown on U.S. Coast Guard required "Maximum Capacity Plates" on the transom of outboard boats. The standards were last updated in 1986, and since then the weight per HP has changed dramatically, with the heavier 4 strokes on the market. The solution to this problem will apparently be a maximum rating for HP, as well as a maximum rating for engine weight. This means that a given boat will be able to handle a higher horsepower 2 stroke outboard on the transom than a 4 stroke. This will become most important with smaller boats, which are more susceptible to changes in weight distribution.

Have you ever wondered what it was like for an outboard motor technician 50 years ago? Below are some questions that a graduate of the Oliver Outboard Motor Service School were expected to know the answers to. These are taken from an Oliver Outboard service school manual from the 50's.

1. Why is a 2 cycle most common in outboard motors manufactured in the USA?

2.What is the most common oil mix in modern outboards?

3.Why is the correct gas-oil mix important?

4.What part requires the most lubrication in an outboard motor?

5.How is the fuel pump operated on the normal two-cycle outboard?

6.Stuck piston rings may be caused from what reason?

7. There is only one way to install a piston in the cylinder.

8.A carburetor mixes the proper oil-fuel ratio.

9.On the two cycle engine, the piston fires every other time

it comes to top dead center.

10.An engine that will not start may be caused by flooding.

Not very high tech, was it?

Elgin was the brand name of outboards sold by Sears. The name was first used in 1946, and was discontinued in 1963.

The early Elgins were made by West Bend.

All Elgin motors made by West Bend had model numbers beginning with 571. We will continue next month.

Source: Laing's Outboards

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