The Four Stroke Engine

Outboard Motor for the Birding Jonboat

ENGINE: Honda 15 HP 4-stroke outboard with electric start

Why we bought a new engine
When you are on a river, the reliability of your motor is the prime consideration. If you are seeking happiness and peace of mind on the water, a high-quality engine that starts every time with no effort is cheap at any price.

Based on my past experience with pull-start outboards, I didn't even consider getting a model without electric start. The extra cost was minimal, and while birding I find myself stopping and starting many times. Note that the electric start models also include a pull rope for manual starting. Just in case you need more exercise.

Why 15 HP?
That was the size and weight that fit our boat. Every boat will have a maximum horsepower rating specified by the manufacturer. Don't exceed it.

Why we bought a 4-stroke engine
I know that 4-stroke engines cost more. And they're heavier for the same amount of horsepower. But they're worth it. Here's why.

Less pollution
Most outboard motors have 2-stroke engines, like lawnmowers. 2-stroke engines are lubricated by the oil that is mixed into the gasoline. The exhaust from a 2-stroke engine is smoky and contains unburned oil, which pollutes the water.

On the other hand, 4-stroke outboard motors have engines like the one in your automobile. The lubricating oil is separate from the fuel. It is not burned, and the exhaust is intrinsically much cleaner and friendlier to the environment.

The EPA has mandated that all outboard motors sold after 2006 must meet the minimum pollution standards that currently are met only by 4-stroke engines. It was important to us, philosophically, to choose this option now.

No mixing of oil and gas
It's very convenient not having to mix oil and gas. With 2-stoke engines, I always had problems with this. For example, say your fuel tank is partially full, and you want to top it off before you head up river. How much oil do you add? I could never be sure my proportions were right. Or, what to do with unused gas at the end of the season? Keep it over the winter? Old, stale, oil-gas mixtures make for hard starting in spring. Now I just pour what's left in the car.

Although many newer 2-stroke engines have oil injection systems so you don't have pre-mix the oil and gas, this feature is not always available on the smaller models. And even with oil injection, water pollution is still the main issue.

Less noise
4-stroke engines run quieter than 2-stroke engines, especially at slower (birding) speeds. This can make a big difference in your comfort level.

Better fuel economy
At slower speeds, 4-stroke engines can get twice the gas mileage of 2-stroke engines. It's not so much the cost of gas as it is the increased range. With a 4-stroke, you can go further up river on the same tank of gas and see more habitat.

No fouled spark plugs
2-stroke engines tend to foul their spark plugs and then sputter and stall. They need more attention to the spark plugs to keep them running properly. Again, this happens more at slower speeds, the speeds birders will tend to travel at.

Why a Honda?
Other manufactures also make 4-stroke outboard engines. I chose Honda because they were the pioneer in this field and have such an excellent reputation for making small 4-stroke engines. So far, our Honda has performed flawlessly. However, you might find a local dealer with whom you want to do business that carries another brand.

Here's one place to start:

http://www.honda-marine.com/