750K maybe! I had 2 buddies back in '75 that both had Mach III's. They went around picking on K's. They had never seen a 75 F at that point. I let them mouth off for a while then proceeded to kick both their asses so bad that I quit after 3rd gear with both! That's one reason I like my F so much and still have it. I was about to take on another of those Kamakazies, a 900 this time, in 3/76 while at Daytona when I broke #2 intake when I missed 2nd doing a power shift while blowing it out. I was looking forward to that but never had the chance.
Jerry, now you know that I love you like a brother, but in this case, you are just so full of shi-ite! I bought a canary yellow 1975 CB750F new in 1978, it was sitting in the packing crate for almost 3 years because it was just so butt-ugly the dealer couldn't give it away, and I I have to tell you, I was so disappointed with it after riding many CB750K's, it was so slow, and handled so bad, Kawasaki dirt bikes with knobby tires could kick it's fat ass!
And handling? What handling? The original Bridgestone tires were made from some kind of black lard, that fat bulbous muffler would grab the road at only moderate cornering angles and lift the back wheel off the ground, and the crappy rear shocks would let it wallow like a fat chick on the disco floor, what a friggin' nightmare, that slug of a thing almost killed me! No wonder I got rid of it at the first opportunity and bought a K1, a far superior bike, in every way!
I've ridden a Mach III many times, and owned a Z900 for several years and I can tell you with all honesty, a CB750F ("F" stands for "Farking fugly") wouldn't be a match for either. Tell you what mate, bring it over here on your next vacation and I'll get my mate Davey to bring his stock Mach III around and you can give him a run, just for old times sake, but you better start working on making up some good excuses as to why he kicked your ass, because you'll need 'em, ha ha!