Yamahas H.P.D.I. (High Pressure Direct Injection) & Evinrudes E-Tec both utilize the injector in the combustion chamber of the cylinder head. Lubrication is via separate pressure feed oil lines to vital areas. According to an engineer I spoke with, the advantage of this on a 2 stroke is the intake tract can be optimized for dry flow as opposed to a fuel laden wet flow design.The problem is physical size of the injector pumps, they are big & bulky.  If technology were to shrink these, is there any future with this in the powersports industry?

There is a future if they can find a way to make the cost of EFI and or direct injected systems about the same as conventional carburation and CDI ignitions.  The reason for the direct injection in two strokes was to comply with new emission standards and decrease fuel consumption, not to increase the power.  There is not any power advantage to direct injection.  The boat, jet ski, and snowmobile engines that use direct injection make a lot of power because they are large displacement engines that are not in a real high state of tune. 

The direct injected engines are expensive to manufacture, repair and expensive equipment is needed to diagnose and repair the electrical systems on these engines.  I do not think that the power sports industry is going to move in this direction unless high emission standards are placed on all of the off road vehicles.