A quote from a 1977 test report:
The K-model is all this plus another 3 percent. It has an edge because it's built and sold as a touring bike, so factors such as ground clearance and weight aren't as significant as they are to a bike with "Super Sport" in its name. Ideally the K model would also have ComStar wheels, dual horns, a rear disc and the F's power, but even without them, it's a fine touring machine tainted only by less than satisfactory suspension compliance. Its 1/4-mile time of 13.33 doesn't seem impressive compared to the F's hot-blooded 12.7, until you realize it's still three tenths quicker than the original CB750, three tenths quicker than the current Yamaha 750, and quicker than the BMW 750. In short it's no slouch, and there's a simple explanation why: the K engine is last year's Super Sport engine with the new accelerator-pump carburetion system.
Because of higher gearing which lets the engine loaf, the K is even smoother than the F2, and therefore a rival to BMW for comfort. Further improvements include new seamless mufflers which look better and quiet the engine's 57.13 horsepowerto 78 dB(A) - a whisper. Redesigned triple-clamp bosses bring the new handlebar closer to the rider, partially to compensate for an inch-longer wheelbase. These changes, along with the new grips and two-stage seat, produce an exceptionally natural feel. It's likely a rider will remain comfortable for a whole tank of gas, which is now five full gallons - enough for 200 miles at a 40 mpg average. Nearly an inch more rear shock travel also contributes to the K's comfort and load-carrying ability. In addition, Honda has fitted the same fat rear weenie that works so well on the heavier GL1000 and Automatic.
Full report here:
http://www.triumf.ca/people/baartman/bike/cb750-77.html
