Hi Anonymous, it should be noted that the reasons EFI lights constant or flashing, will or will not start, turns over or not conditions varies from the year, make, and model and you should always refer to your owners/service manual for proper diagnostic procedures. It should also be noted that any type of prior work or event IE: adding accessories, electrical curiosity/adventures, laying bike down/crashes, rainstorms/bike washings just before EFI light issues started can be significant hints/aids into tracking down the gremlin, also carry the appropriate jumper wire to access fault codes to reduce the risk of being stranded or towed, that being said the usual suspects are:
1. Faulty Fuel Pump, fuse or system relay switch.
2. Battery starting to fail due to old age/damage, perform a load test.
3. Discharged battery, check battery terminals for damage or corrosion, check the battery cables at "BOTH" ends for loose, corroded, or broken connectors, "INSIDE" and outside the cable harness, perform connector wiggle test and check cables with an ohmmeter if necessary.
4. Faulty switches/sensors: run/off, ignition, clutch lever, neutral, side stand, tip over, fuel, and or their connections.
5. Broken wire or worn insulation exposing wire to a ground situation especially inside wire harness at tight bends around fairing brackets, under dash panels, under fuel tanks over cylinder heads etc. Many harnesses are open on the ends that will allow water to enter and accumulate at v-bends.
Dielectric grease and contact cleaner are your best friends for wire/cable/harness connectors, look for corroded, broken, or loose pins/sockets. Good luck and have a nice day.
Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/gregg_c0ec1df182c7330e