1. Vacuum leaks: A vacuum leak can cause the engine to run lean and cut out. Check the vacuum lines and make sure they are properly connected and not cracked.
2. Fuel supply problems: A clogged fuel filter or fuel line, or a faulty fuel pump, can cause the engine to cut out. Check the fuel system components and make sure they are in good condition.
3. Ignition problems: A faulty spark plug, ignition coil, or wiring problem can cause the engine to cut out. Check the ignition components and make sure they are in good condition.
4. Engine problems: A mechanical problem such as a worn piston ring or a faulty camshaft can cause the engine to cut out. If the problem is internal, it may require disassembly of the engine to diagnose and repair.
If you are not able to identify and fix the cause of the cutout yourself, it is recommended that you take the ATV to a qualified mechanic for further diagnosis and repair.
