Ran my RE500 hard from day one. Had to adjust valves, carb, and chain frequently and it used a little oil. Now with 6000 miles on the clock it runs great, cruises at 60-65 (indicated) and seldom needs any kind of adjustment. Now, by running hard, I don't mean abuse. Just higher speeds than recommended. Even on the backroads here in Ky you will get run over doing 30-35 mph so you have to go faster. The main things are not to let it run hot or low on oil. As for your bike cruising at 70.....it won't do it. The most you can expect is about 60 mph........Dew.