2 stroke injection experiences?

[John Faubion]

> Anyone on the list have experience of single or multi cylinder 2 stroke 
> injection form a practical point of view?

I have been considering this for my race kart. Since I'm portly (for kart
racing!) at 210 lb., the only real problems are:
 1) finding an injector that is small enough and
 2) the weight penalty of the ECM and battery to power the system
 3) at 14,000 plus RPM the time to fire an injector is only ~4 ms

That last one is probably the killer. Four milliseconds is beyond the
current limits of injector technology. The smallest injectors I've found
are 13.8 lb./hr and an 18hp 100cc kart engine would only need about 8.5
lb./hr. So using a electric pump for a motorcycle at around 15 psi would
flow about right. This may not allow the injector to flow properly which
may add more problems than a Walbro. Even if we did find the right size
injector and could fire it fast enough, we would still need an ECM (<lb.),
pump(~lb.), and battery(10-12lbs). Since I'm rather portly (for kart
racing!) at 210 pounds, I currently run around 15-20 pounds over my class
weight. EFI probably won't improve power enough to compensate for the extra
10-15 pounds added. This additional weight would kill me, but if your
currently adding that much ballast then it might be viable.