You’ll be much faster on the TZ, part of it is not that you have been racing but how to ride a 2 stroke, it is much different than the 4 strokes. I have a full WGP 250 Honda kit motor, eventually I will put it in the next bike i build, but I ride a stock NXA RS250, I could put the kit cylinders and pistons in it, but I don’t. I even run it a little rich, and have the squish pretty conservatively set up. No craze advance on the timing either. I just ride it. Ride it and you will be amazed at how fast you are on it once you get used to the power delivery. It’s fun to come out of a corner drafting the 600’s.
Be ready to down shift ALOT as you enter corners or it will just go blaaaaa instead of driving out like it can.
So, finally rode the TZ in anger (lol) at Cycle Jam and have to say, it;s the most fun i've ever had on a race bike. Cant wait to ride it next weekend at PIRC