* Empty gas tank: Make sure the gas tank has enough fuel.
* Clogged fuel filter: Replace the fuel filter if it is dirty.
* Faulty fuel pump: Check the fuel pump to ensure it is working properly.
* Faulty fuel injector: Check the fuel injector to ensure it is working properly.
* Electrical-related issues:
* Dead battery: Check the battery to ensure it is charged and in good condition.
* Loose or disconnected electrical connections: Check all electrical connections to ensure they are tight and properly connected.
* Faulty ignition switch: Check the ignition switch to ensure it is working properly.
* Faulty starter: Check the starter to ensure it is working properly.
* Mechanical-related issues:
* Seized engine: Check the engine to ensure it is not seized.
* Broken timing chain: Check the timing chain to ensure it is not broken.
* Faulty piston: Check the piston to ensure it is not damaged.
* Faulty valves: Check the valves to ensure they are working properly.
If you are unable to identify and resolve the issue, it is best to take your Yamaha 660 Raptor to a qualified mechanic for further diagnosis and repair.
