At the beginning of this season my tachometer was only working occasionally. the more i rode it the problem corrected itself. I just returned from vacation (gone for two weeks) and the problem was re-appeared. It flutters and than stops working. Where should i begin the trouble shooting stage. I have shook the tach wires with no results. Sometimes when i turn the bike off, than back on again it will start to work than drop to zero and start to fludder.