The Polaris Sportsman 850, a workhorse of the ATV world, is known for its power and reliability. But even the toughest machines can face hiccups, and starter problems are among the most common issues reported by owners. A failing starter can leave you stranded on the trail or unable to tackle essential chores, making understanding the potential causes and solutions crucial for any 850 owner.

That Dreaded Click: Recognizing Starter Issues

The most obvious sign of a starter problem is the infamous "click, click, click" when you turn the key. However, a weak battery can also cause similar symptoms, so it’s essential to differentiate. A healthy starter should engage and crank the engine quickly. Other telltale signs include:

  • Slow or labored cranking: The engine turns over sluggishly, taking longer than usual to start.
  • Intermittent starting: The ATV starts sometimes but not others, with no apparent pattern.
  • Grinding noises: An unpleasant grinding sound during starting suggests damaged gears within the starter.
  • Complete silence: Nothing happens when you turn the key; no click, no crank, nothing.

Ignoring these warning signs can lead to more significant problems down the line. Identifying the issue early can save you time, money, and the frustration of being stuck in the middle of nowhere.

The Usual Suspects: Common Causes of Starter Failure

Several factors can contribute to starter problems in a Polaris Sportsman 850. Let's explore the most common culprits:

1. Weak or Dead Battery: This is the most frequent cause. A battery that's not holding a charge or is simply too old won't provide enough power to the starter motor.

2. Corroded Connections: Corrosion on the battery terminals, starter solenoid, or ground connections can impede the flow of electricity. Even a small amount of corrosion can significantly reduce the voltage reaching the starter.

3. Faulty Starter Solenoid: The solenoid acts as a switch, sending power from the battery to the starter motor. A failing solenoid may click but not engage, or it may fail to send any power at all.

4. Worn Starter Motor: Over time, the starter motor itself can wear out. Brushes wear down, bearings fail, and the armature can become damaged.

5. Damaged Starter Clutch (Bendix): The starter clutch, also known as the Bendix drive, engages the starter motor with the engine's flywheel. A damaged or worn Bendix can slip or fail to engage properly, resulting in grinding noises or a failure to crank.

6. Wiring Issues: Damaged or broken wires in the starting circuit can interrupt the flow of power. This is especially common in areas exposed to vibration or the elements.

7. Loose Connections: Vibration and rough terrain can loosen connections in the starting circuit, preventing proper electrical flow.

8. Engine Problems: Although less common, engine problems like excessive compression can put extra strain on the starter, causing it to fail prematurely.

Troubleshooting Like a Pro: Step-by-Step Diagnosis

Before you start tearing things apart, follow these steps to diagnose the problem systematically:

Step 1: Battery Check:

  • Visual Inspection: Check the battery terminals for corrosion. Clean them thoroughly with a wire brush and baking soda solution.
  • Voltage Test: Use a multimeter to check the battery voltage. A fully charged 12-volt battery should read around 12.6 volts. If it's below 12 volts, charge the battery and retest. If it still doesn't hold a charge, the battery may be bad.
  • Load Test: A load test simulates the draw of the starter motor. Most auto parts stores can perform a free load test on your battery.

Step 2: Connection Inspection:

  • Trace the Wiring: Follow the wires from the battery to the starter solenoid and then to the starter motor. Look for any signs of damage, such as frayed wires, loose connections, or corrosion.
  • Clean Connections: Disconnect and clean all connections in the starting circuit. Use a wire brush or sandpaper to remove any corrosion. Apply dielectric grease to protect the connections from future corrosion.
  • Tighten Connections: Ensure all connections are tight and secure.

Step 3: Solenoid Test:

  • Bypass Test: Carefully bypass the solenoid by connecting the two large terminals with a screwdriver. Be extremely careful when doing this, as it can create sparks. If the starter motor engages and cranks the engine when you bypass the solenoid, the solenoid is likely faulty.
  • Voltage Test: Use a multimeter to check for voltage at the small terminals on the solenoid when you turn the key. If you're not getting voltage to the solenoid, the problem may lie in the ignition switch or wiring.

Step 4: Starter Motor Test:

  • Direct Power Test: Disconnect the starter motor from the solenoid. Use jumper cables to connect the starter motor directly to the battery (positive cable to the starter terminal, negative cable to the starter housing). If the starter motor spins freely, it's likely good. If it doesn't spin or spins slowly, the starter motor is faulty.

Step 5: Bendix Inspection (if applicable):

  • Visual Inspection: If you suspect a problem with the Bendix, remove the starter motor and inspect the Bendix gear. Look for worn or damaged teeth.
  • Manual Test: Try to manually extend and retract the Bendix gear. It should move smoothly and freely. If it's stiff or binding, it may need to be cleaned or replaced.

Step 6: Check the Engine:

  • Compression Test: If the starter is struggling to turn the engine over, consider performing a compression test to rule out engine problems.

DIY Repairs: When to Tackle It Yourself

Some starter problems are relatively easy to fix yourself, while others require professional help. Here's a breakdown:

DIY-Friendly Repairs:

  • Cleaning corroded connections: This is a simple and effective way to resolve many starting issues.
  • Replacing a faulty solenoid: Solenoids are relatively inexpensive and easy to replace.
  • Replacing a weak battery: This is a straightforward task that most owners can handle.
  • Tightening loose connections: A quick check and tightening of connections can often resolve intermittent starting problems.

Repairs Best Left to the Pros:

  • Replacing a worn starter motor: This requires removing the starter motor, which can be difficult depending on the ATV model.
  • Repairing or replacing a damaged Bendix: This requires specialized tools and knowledge.
  • Diagnosing and repairing wiring issues: This can be time-consuming and requires a good understanding of electrical systems.
  • Addressing engine problems: Engine repairs are best left to qualified mechanics.

Preventative Maintenance: Keeping Your Starter Healthy

Prevention is always better than cure. Here are some tips to keep your Polaris Sportsman 850 starter in top condition:

  • Regular Battery Maintenance: Keep your battery clean, charged, and properly maintained. Use a battery tender during periods of inactivity.
  • Inspect Connections Regularly: Check the battery terminals, solenoid connections, and ground connections for corrosion. Clean them as needed.
  • Use Dielectric Grease: Apply dielectric grease to all electrical connections to protect them from moisture and corrosion.
  • Avoid Excessive Cranking: Don't crank the engine for extended periods. If the engine doesn't start after a few attempts, stop and diagnose the problem.
  • Proper Storage: If you're storing your ATV for an extended period, disconnect the battery or use a battery tender to prevent it from discharging.
  • Consider a High-Performance Battery: If you frequently ride in cold weather or use your ATV for heavy-duty tasks, consider upgrading to a high-performance battery.

Frequently Asked Questions

Q: Why is my starter clicking but not turning over?

A: This usually indicates a weak battery or a faulty starter solenoid. Check the battery voltage and the solenoid connections.

Q: How do I clean corroded battery terminals?

A: Disconnect the battery cables and clean the terminals with a wire brush and a baking soda solution (mix baking soda with water to form a paste). Rinse with water and dry thoroughly before reconnecting.

Q: What is a starter solenoid, and what does it do?

A: The starter solenoid is an electrical switch that relays power from the battery to the starter motor. It allows a small current from the ignition switch to control a larger current to the starter.

Q: How can I test my starter solenoid?

A: You can test the solenoid by bypassing it (carefully connecting the two large terminals with a screwdriver) or by using a multimeter to check for voltage at the small terminals when you turn the key.

Q: Is it difficult to replace a starter motor myself?

A: It depends on your mechanical skills and the specific ATV model. Some models are easier to access than others, but it generally involves removing body panels and disconnecting electrical connections.

Conclusion

Starter problems on a Polaris Sportsman 850 can be frustrating, but by understanding the common causes, following a systematic troubleshooting process, and performing regular maintenance, you can keep your ATV starting reliably. Remember to prioritize safety when working with electrical components and don't hesitate to seek professional help if you're uncomfortable with any of the repairs.