Hybrid 4 vs Traditional 2-Stroke
So how does the Hybrid 4® engine work? Like a two-stroke, the gas/oil fuel mixture is drawn into the crankcase on the piston upstroke. As the piston comes down, back-pressure closes the intake reed valve. The fuel charge is compressed by the piston and pumped through another one-way reed valve into the Power Boost Chamber beneath the crankcase.
And similar to a four-stroke engine, there are two down-stroke “pumps” to each intake event, which pressurizes and compounds the fuel charge within the Power Boost Chamber. This adds a super-charging effect. But unlike a traditional four-stroke engine, because the lubricant is mixed with the fuel charge, it bathes bearings, valve train and friction surfaces as it travels from the crankcase, through the Power Boost Chamber and then to overhead valves. This fuel-born lubrication system assures that the engine is fully lubricated, no matter how itís turned or tilted, and no matter how long it is run out of position.
With precisely-timed valves controlling intake and exhaust functions, combustion is maximized and emissions are significantly reduced.