Thinking about Suter Racing’s MMX500 offering—its $130,000 replica 500 GP two-stroke V-4—I realize why they gave this bike four-stroke-style throttle body fuel injection. They did it because selling the bike with carburetors would have left its buyers helpless in the face of how it used to be done—confronted by main jets, slides, needle jets, pilot jets, needles, air correction jets, and the various heights of jet shrouds. An experienced tuner carried literally hundreds of these items to every race. All this is meaningless to modern riders.
With the single exception of Honda’s PGM injection, used around 1993, all those hallowed slip, grip, and high-side 500 GP bikes were fueled by carburetors. That meant that jetting had to go up and down with atmospheric pressure and temperature, the main variables of…
