The MachIII was the 500 triple. It had two engine power modes... bog and wheelie. A friend of mine had one of those 750 Mach IVs with expansion chambers and some porting. It made a LOT of horsepower in the most unpleasant manner possible. I could get around the Angeles Crest much more quickly on my much heavier CB750F. The good old Honda didn't have the flexy flyer frame and didn't tend to spin the rear wheel at every opportunity.