The Ninja 300 is fuel injected (without any doubt). As I said before I owned one. It does NOT have an oxygen sensor (federal emissions cali might have one), which the CBR 250 has as well as the TU205X. I never mentioned making a wheeler out of the GZ250, just that I own one and at $ 650 with 3300 miles one of the best bike purchases I ever made.
http://www.topspeed.com/motorcycles/...-ar160322.html
Viking, you can check my fuel logs to compare the bikes I have owned, and I know the fuel delivery system on each one.
The OE Metzler tire on the back of my GZ250 is rated for a max of 661 pounds, more than the OP's proposed trike bike and his weight combined, on all 3 wheels.
11 different motorcycles in my current fuel log on this site.
regards
Mech