1. Clogged Carburetor: A clogged carburetor can restrict the flow of fuel into the engine, leading to a lean fuel mixture. When the choke is turned on, it enriches the fuel mixture, allowing the engine to run more smoothly.
2. Dirty Fuel Filter: A dirty fuel filter can restrict the flow of fuel to the carburetor, causing a lean fuel mixture. When the choke is turned on, it bypasses the fuel filter, allowing more fuel to reach the carburetor.
3. Vacuum Leak: A vacuum leak can cause the fuel mixture to become lean, leading to engine stalling. When the choke is turned on, it increases the vacuum in the intake manifold, compensating for the leak and allowing the engine to run more smoothly.
4. Damaged Choke Plunger: The choke plunger is responsible for regulating the flow of air and fuel into the engine. If the choke plunger is damaged or worn out, it may not be able to fully close, leading to a lean fuel mixture. Turning on the choke can help compensate for the damaged choke plunger and allow the engine to run more smoothly.
5. Faulty Fuel Pump: A faulty fuel pump may not be able to provide enough fuel pressure to the carburetor, leading to a lean fuel mixture. Turning on the choke can increase the fuel pressure, allowing the engine to run more smoothly.
If your ATV only runs with the choke on, it's important to identify and fix the underlying issue as soon as possible to prevent further damage to the engine.
