Thanks for the information. All of it was interesting to read and informative. I actually work for Keihin so I obviously support carburetors but in a world of increasing emissions regulations it's inevitable that 2-strokes will all move to fuel injection in order to survive. It's very interesting as to what it takes for EFI to work in 2-strokes reliably.

Throttle body injection, crankcase injection or port injection does not or has not been able to make a two stroke with a tuned pipe meet the emissions standards of most countries.  I was able to make some of the test EFI test engines we were working on in the early 1990s meet the standards at the torque peak where the scavenging and pipe are working together at their best.   The emissions were off the charts when you are 1000 RPM from the torque peak. 

Some of the military drone engines are using EFI but the governments around the world do not care about emissions on the military stuff.

The boating and snowmobile industry has had success with direct injection into the combustion chamber since around 1995. The price of the two stroke boat engines just about doubled in price with the direct injection technology.  The cost of repair of the direct injection systems are very expensive. 

Engines that operate at a fairly constant RPM where the RPM does not change 1000 RPM or more per second, direct injection seems to work but has not been successful in the two stroke racing engines. 

Rumor has it that KTM will be releasing fuel injected two stroke dirt bikes this year.  It will be interesting to see what they have done and will it be possible to retune it after changing the tuned pipe, ports, reeds or air filter?