HI Allan it may be late for this replay but its been a while since I came on the site, I do hope by now you have resolved this issue but if not... here is what I have found on mine, as far as the overheating yes mine did or does the same thing as you discribe I tried everything I thought may cause this problem and it is better now, but not what I would sxpect it to be. Anyway I flushed and changed the fluid in the radiator changed the thermostat and replaced the cap with a higher prsssure new one also added a manual switch to the coolant fan to turn it on when in traffic or when running it at higher rpms in the warmer weather, also took the the plugs out off the carb idle screw and back it out to 2 and 3/4 turns out to let it run alittle ritcher at idle. Don´t know if one of these alone is the culprit or all in conjunction have made the difference, but it has. Hope this helps you and others with this issue. As far as the knocking wouldn´t know what it could be without hearing it but sounds like either the cam chain is slapping in there or you need to adjust the valves. Good luck! G.R.