At least from what I've heard on this forum, EFI for the gen1 tends to be difficult to tune and with marginal, if any, benefits over a well tuned carb setup. IIRC twistedmax used to have EFI on his bike and later went back to carbs. What is your motivation for going EFI?
I've done a fair bit with EFI tuning(and even controller construction),not on Vmax, but on modern snowmobiles with EFI and it's not as simple as it might seem. For as simple a device as a carburetor appears to be, it's surprisingly complex to emulate with a computer. OEMs (we've communicated with Bombardier engineers) spend hundreds to thousands of hours tuning in EFI settings to get that "flawless" fueling people expect when they buy a new (car, bike, snowmobile). After loads of dyno time, there's even more "real world" use, which always seems to pull a few more flaws out of the woodwork. Correct one, it causes another, it can be maddening.
We programmed a closed-loop feedback system on a custom ECU(piggybacking the stock ECU) to allow the engine to automatically tune itself for varying ethanol contents in fuel. i.e it's now a "flex fuel" vehicle. Theoretical calculations made up some base test maps, but despite being "ideal" values, the motor just didn't run as good as it used to. Flat spots here and there, a laggy throttle response in places, too touchy in others. Took a lot of hours on the dyno making minute adjustments to get it to run "seamlessly" on any fuel dumped in the tank. Essentially to make it run as good as stock. And it still doesn't(well it does if we just enter a "zero field" in the piggyback, which puts it back to stock), but it's good enough that someone unfamiliar with the engine wouldn't notice.
Good luck with it.
