The Yamaha Big Bear 350, a workhorse of an ATV, is renowned for its reliability and ruggedness. However, even the toughest machines can experience hiccups, and a common frustration for Big Bear 350 owners is a malfunctioning electric start system. This can leave you stranded in the field or, at the very least, significantly delay your work or recreational riding. Understanding the potential causes and troubleshooting steps is crucial to getting your Big Bear back up and running quickly.

Why Won't My Big Bear 350 Start Electrically? Let's Investigate

Before tearing into your ATV, let's systematically explore the most common culprits behind a non-responsive electric start. We'll start with the simple checks and move towards the more complex components.

1. The Obvious Suspect: The Battery

A weak or dead battery is the most frequent reason why your Big Bear 350's electric start refuses to cooperate. Even if your headlights seem bright, the battery might not have enough amperage to crank the engine.

  • Visual Inspection: Check the battery terminals for corrosion. Clean them thoroughly with a wire brush and battery terminal cleaner if necessary.
  • Voltage Test: Use a multimeter to check the battery voltage. A fully charged 12-volt battery should read around 12.6 volts or higher. If it's significantly lower (below 12 volts), it needs charging.
  • Load Test: Even if the battery shows a good voltage, it might fail under load. A load test measures the battery's ability to deliver power when starting the engine. Most auto parts stores offer free battery load testing.
  • Battery Age: Batteries have a lifespan. If your battery is more than a few years old, it might be time for a replacement, regardless of the voltage reading.

2. Checking the Fuses: Don't Overlook the Basics

Fuses are designed to protect your electrical system from overloads. A blown fuse in the starting circuit will prevent the electric start from working.

  • Locate the Fuse Box: Consult your owner's manual to find the location of the fuse box. It's usually under the seat or near the battery.
  • Inspect the Fuses: Visually inspect each fuse for a broken filament. A blown fuse will have a noticeable gap.
  • Replace Blown Fuses: Replace any blown fuses with a fuse of the exact same amperage. Using a higher amperage fuse can damage your electrical system.
  • Recurring Blown Fuses: If a fuse blows repeatedly, there's a short circuit somewhere in the system. You'll need to trace the wiring to find the problem.

3. The Starter Solenoid: The Middleman

The starter solenoid is a heavy-duty relay that connects the battery to the starter motor. If it's faulty, it won't allow current to flow, preventing the engine from cranking.

  • Listen for a Click: When you press the start button, listen for a clicking sound from the solenoid. A click usually indicates that the solenoid is receiving power but might not be making a good connection internally. No click suggests a problem with the solenoid's power supply or the solenoid itself.
  • Bypass the Solenoid (Use Caution!): This is a troubleshooting step that should be performed with extreme care. Use a screwdriver to carefully bridge the two large terminals on the solenoid. Wear eye protection and be prepared for sparks. If the engine cranks, the solenoid is likely faulty and needs to be replaced. Never do this if you suspect a fuel leak.
  • Multimeter Test: Use a multimeter to check for voltage at the solenoid terminals when the start button is pressed. You should see battery voltage at the output terminal when the start button is engaged.

4. The Starter Motor: The Engine's Cranking Muscle

The starter motor is responsible for turning the engine over until it starts. If it's damaged or worn out, it won't be able to do its job.

  • Symptoms: A failing starter motor might make a grinding noise, turn slowly, or not turn at all.
  • Direct Power Test: Disconnect the wire from the starter solenoid to the starter motor. Using jumper cables, carefully connect the positive cable to the starter motor terminal and the negative cable to the engine block (ground). If the starter motor spins, the problem lies elsewhere in the circuit. If it doesn't spin, the starter motor is likely the culprit.
  • Internal Inspection (Advanced): Removing the starter motor and inspecting the brushes and commutator can reveal significant wear or damage. This is a more advanced procedure that might require specialized tools.

5. The Start Button: The Trigger

A corroded or faulty start button can prevent the electrical signal from reaching the solenoid.

  • Visual Inspection: Check the start button for any signs of damage or corrosion.
  • Contact Cleaner: Spray electrical contact cleaner into the start button assembly to remove any dirt or corrosion.
  • Continuity Test: Use a multimeter to check for continuity across the start button terminals when the button is pressed. If there's no continuity, the button is faulty and needs to be replaced.

6. Wiring Issues: The Invisible Enemy

Damaged or corroded wiring can disrupt the flow of electricity and prevent the electric start from working.

  • Visual Inspection: Carefully inspect all wiring connections in the starting circuit for loose connections, corrosion, or damaged wires. Pay close attention to ground connections.
  • Wiring Diagram: Consult a wiring diagram for your specific Big Bear 350 model. This will help you trace the wiring and identify potential problem areas.
  • Multimeter Test: Use a multimeter to check for continuity in the wiring. Look for breaks or shorts in the wires.
  • Ground Connections: Ensure that all ground connections are clean and tight. Poor ground connections can cause a variety of electrical problems.

7. The Neutral Safety Switch: Keeping You Safe

The neutral safety switch prevents the engine from starting in gear. If it's faulty, it might prevent the electric start from working even when the ATV is in neutral.

  • Location: The neutral safety switch is typically located near the gear shift lever.
  • Testing: Consult your service manual for the specific testing procedure for your model. You can often bypass the switch temporarily (for testing purposes only) by disconnecting the wires and connecting them together. Never operate the ATV with the neutral safety switch bypassed for extended periods.

8. The Stator: Generating the Spark

While the stator primarily charges the battery, a severely damaged stator can sometimes impact the starting system, especially if it's not providing adequate voltage. This is less common, but worth considering if other components check out. Test the stator output according to your service manual.

Specific Considerations for the Yamaha Big Bear 350

  • Model Year Variations: Be aware that there might be slight differences in the electrical system depending on the specific year of your Big Bear 350. Always consult your owner's manual or a service manual for your particular model.
  • Aftermarket Accessories: If you've added any aftermarket accessories (lights, winches, etc.), they might be drawing excessive power and contributing to battery drain. Disconnect them temporarily to see if the starting problem improves.
  • Previous Repairs: If the ATV has been previously repaired, check the quality of the repairs. Loose connections or incorrect wiring can cause problems.

Frequently Asked Questions

  • Why does my Big Bear 350 click when I try to start it? A clicking sound usually indicates a weak battery or a faulty starter solenoid. The solenoid is receiving power but not making a good connection internally.
  • How do I know if my starter motor is bad? A bad starter motor might make a grinding noise, turn slowly, or not turn at all. A direct power test can help confirm if the starter motor is the problem.
  • Where is the fuse box located on my Big Bear 350? The fuse box is typically located under the seat or near the battery. Consult your owner's manual for the exact location.
  • Can I use a higher amperage fuse if my original fuse keeps blowing? No, never use a higher amperage fuse. This can damage your electrical system. Find the short circuit causing the fuse to blow.
  • Is it safe to bypass the starter solenoid? Bypassing the starter solenoid should only be done for testing purposes and with extreme caution. Wear eye protection and be prepared for sparks.

Conclusion

Troubleshooting electric start problems on your Yamaha Big Bear 350 can seem daunting, but by systematically checking each component and following the steps outlined above, you can often diagnose and fix the issue yourself. Remember to always prioritize safety and consult your owner's manual or a service manual for specific instructions and diagrams.