Two direct injection systems are used in transport
two stroke engines: low-pressure air assisted
and high pressure direct injection. The Orbital low
pressure air assisted direct injection system utilizes
a single injector to inject the gasoline fuel and compressed
air into the combustion chamber. The Orbital
system is used in motor scooters manufactured
by Aprilia, Piaggio, Peugeot and Kymco, in outboard
motors manufactured by Mercury and Tohatsu,
and in personal watercraft manufactured by Bombardier
[2, 3]. The high pressure direct injector system
is the traditional four stroke direct injection engine
technology. This system is now available on
marine engines and watercraft [1] and many other
applications are expected shortly.