The bikes having ignition problems. Theres three coils in the stator down on the engine. The coils develope the energy for the ignition mostly. One of the coils in called the Exciter. If the circuit for the exciter or the exciter it self goes bad the bike will do just what you say. Unplug the CDI module. Check the resistance of pairs of wires. Blue and White wires should have 85 Ohms. Pink and Green/engine ground should have 135 ohms. Light Blue and Brown wires should have 207 ohms. Your exciter wires probably don´t have 135 Ohms. Its probably infinite. If you do have 135 ohms. then you have a bad CDI. I´ve got a replacement . Its new and replaces the TIA10-20. Send me an e-mail address and I´ll mail back all the info on it. ----- Dave