Since the tightening of anti-pollution standards, outboard engine manufacturers have chosen 4-stroke technology. All except one: Evinrude, which has remained faithful to 2-stroke. By adopting modern technologies such as direct injection, this manufacturer has succeeded in meeting the anti-pollution standards. A bold move, but one that is paying off today. The 2-stroke is back in the spotlight in motorcycles and even cars.
Couple
The torque is not spread over the same rpm ranges between a 2 and a 4 stroke. On a 4-stroke, the maximum torque is around 3500 rpm. On a 2-stroke, it occurs earlier, around 2000 rpm. The 2-stroke, by offering torque more quickly, allows for rapid lift-off.
In addition, with fewer mechanical parts (no valves, no rockers...), the 2-stroke engine is lighter. It is therefore suitable for small boats that do not have much rear volume, even if larger boats such as helmsmen are also concerned by this technology.
Pollution
Evinrude engines meet the same pollution standards as other engines. This has been achieved by no longer mixing the lubricating oil with the fuel, as was previously the case. The fuel is now injected directly onto the piston crown, while the oil is injected into the engine at the appropriate points for lubrication. From now on, 2-stroke engines do not smoke at all.
Reliability
With fewer moving mechanical parts, the risk of breakage is reduced and reliability is increased. In fact, Evinrude guarantees its motors for 5 years without overhaul!
Consumption
Since the adoption of direct injection, the consumption of 2-stroke engines has dropped drastically. The electronics automatically manage the quantity of fuel to be injected according to the engine speed or temperature. As a result, Evinrude engines have the lowest fuel consumption rates on the market today.
Noise pollution
At idle, a 4-stroke engine can hardly be heard. It is true that in this area, the 2-stroke is less efficient, slightly noisier. But as soon as you accelerate, the noise level becomes equivalent between these 2 technologies. No, the 2-stroke does not make more noise!
