It mostly doesn't turn on to start with but will suddenly come on about half a mile down the road, sometimes riding normally, sometime only if I rev the nuts of it. Pilot lighworks OK and the main beam/pass light works OK. Brake light and indicators are fine. Once it comes on it statys on, except once while pootling through a 40MPH limit, it came back on when I hit the national speed limit bit. Could this be a battery/regulator problem?