I always thought the K7/8 made good commuter bikes, because they narrowed and lowered the saddle and added the hi-idle PD choke for the lean-burn engines. This lets you fire it up and by the time it is backed out of the garage, you can ride off with the choke still engaged, and not stumble at the first stop sign - and the plugs last the longest of all of these bikes. If you adjust the earlier carbs to do this (a la the K0-K2), the result in commuter service is short sparkplug life from a too-rich low RPM range, below 2000 RPM. Today, if the valve guides are changed to bronze instead of the OEM cast iron, these engines can last a long, long time, like the earlier ones - especially if you also install the modern rubber pucks under the rocker towers while you're in there, to preclude their typical oil weeps.