01 April 2020 | Tahiti
Russ Whitford | perfect
In this age of global warming/climate change, Lisa and I thought we would do our small part. We were forced to buy a new outboard motor in Panama when our venerable Mercury 15 hp 4 stroke died. The only suitable motor available was a Suzuki 15hp 2 stroke. Last week we replaced it with the new Mercury 20hp, 4 stroke EFI (electronic fuel injected). The new Mercury (and our old one) has the “Ultra-low Emissions” sticker.
The Suzuki has been a faithful motor for these two years. It starts easily, every time and I have not had the cover off the engine in the entire two years. We use this motor almost every day, it has a lot of miles on it. There was absolutely no reason for us to buy a new motor, Suzuki was serving our needs well.
But! The Suzuki used a lot of gas. We had to mix oil in the gas too. Our old Merc had a 3 gallon tank, the Suzuki came with a 6.3 gallon tank. Good thing! I bet the Suzuki and old Merc emptied their tanks after the same miles of use. Could it be that the Suzuki used double the gas of the Merc? I do not have scientific measurements but I believe it to be true.
The Suzuki (and all two strokes) send about 25% of the raw gas out the exhaust without burning it. There are ways to reduce this but power is reduced as well. Two strokes are also “peaky” on power. They produce their power at higher RPM. We always ran the Suzuki at about 75% power to stay on a nice plane. It just sounded like it was grinding itself up all the time. The Mercs (old and new) maintain a nice plane at less than 1/3 power! Being peaky, the Suzuki required three different propellers. We had a two person, three person and four person prop. I believe the new Merc will plane just fine with the stock prop and four people. But we are under Covid19 quarantine here and can't take extra passengers to test.
Are we really doing our part for the environment? Not really, we will sell the Suzuki to a local fisherman and it will continue to smoke and suck gas. The energy needed to manufacture the Mercury may not be offset by the fuel we save with it. I'll be honest, we bought it 'cause we wanted it. It is convenient to have fuel savings, we don't have to store as much gas onboard in remote areas or fill the tank as often. After talks with Mercury engineers and Pro Boats in California, I was convinced the EFI would be trouble free as well. Of course, the Suzuki trouble free as well.
The design of the Merc we believe is a breakthrough. Outboard motors have the tiller offset to the port side. The idea is that sitting on the back seat of a boat, the skipper can sit in the middle and the tiller falls easily in the left hand. RIB (rigid bottom inflatables) require sitting on the side tube. That puts the tiller quiet far from the driver. The driver has to lean over to reach the tiller. This isn't a big problem for me but Lisa and other women, often sit on the port side where the tiller is close at hand. The new Merc has a tiller that is adjustable from side to side, and up and down! With tiller centered, it is easily within reach when I sit up comfortably. We may even swing it more to the right for Lisa.
I will say that starting the EFI motor is a little harder. One must pull the starter rope all the way to give enough revolutions for the EFI to fire. It usually takes two, long pulls. It is not hard to pull but requires more total effort. The old Suzuki, and other carburetor engines, just need one compression stroke to fire, a short pull. But the power at low rpm, quiet and comfortable ergonomics make the Mercury a real winner. Plus, we can hold our heads up high appearing to be “green.”