The Polaris Xplorer 400, a stalwart of the ATV world, built from 1995 to 2002, is known for its ruggedness and utility. However, like any machine with age and use, the Xplorer 400 can develop a range of problems. Understanding these common issues is key to keeping your Xplorer 400 running strong and enjoying its versatile capabilities for years to come.

So, You've Got an Xplorer 400? Let's Talk Problems.

Owning a vintage ATV like the Polaris Xplorer 400 can be incredibly rewarding, offering a blend of classic design and practical performance. But let's be honest, these machines are getting on in years, and that means dealing with potential problems. Here's a breakdown of some of the most common issues Xplorer 400 owners face, and how you can tackle them.

The Usual Suspects: Common Mechanical Issues

Let's dive into the nitty-gritty. These are the mechanical gremlins that tend to plague the Xplorer 400.

1. Carburetor Clogs and Fuel Delivery Problems:

This is probably the most common issue. The Xplorer 400 uses a carburetor, and over time, especially with ethanol-blended fuels, the small jets and passages inside can become clogged. This leads to:

  • Hard starting: The engine struggles to get enough fuel to fire up.
  • Rough idling: The engine idles erratically, or stalls frequently.
  • Poor performance: Lack of power, hesitation during acceleration, and overall sluggishness.

The Fix: The best solution is a thorough carburetor cleaning. You'll need to remove the carb, disassemble it carefully, and clean all the jets and passages with carburetor cleaner and compressed air. Consider replacing the fuel filter and fuel lines as well. A carburetor rebuild kit is often a good investment.

2. Electrical Gremlins:

Older ATVs are notorious for electrical problems. The Xplorer 400 is no exception. Look out for:

  • Dead battery: Batteries degrade over time. A weak battery can cause starting problems.
  • Faulty stator: The stator generates the electrical power to charge the battery. If it fails, the battery won't charge, and the ATV will eventually die.
  • Wiring issues: Corrosion, broken wires, and loose connections can cause a variety of electrical problems, from lights not working to the engine not starting.
  • Faulty CDI (Capacitor Discharge Ignition) unit: This unit controls the timing of the spark. A failing CDI can cause intermittent starting problems or a complete no-start condition.

The Fix: Start by checking the battery voltage and connections. Use a multimeter to test the stator output. Inspect the wiring harness for any damage or corrosion. Clean and tighten all connections. If the CDI unit is suspected, it can be tested with a multimeter, or by swapping it with a known good unit.

3. Cooling System Problems:

Overheating can quickly damage your engine. Watch out for these cooling system issues:

  • Leaking radiator: Radiators can develop leaks over time, especially at the seams.
  • Faulty thermostat: A thermostat that's stuck closed will prevent coolant from circulating properly, leading to overheating.
  • Clogged radiator fins: Mud and debris can block the radiator fins, reducing its cooling efficiency.
  • Water pump failure: The water pump circulates the coolant. If it fails, the engine will overheat.

The Fix: Regularly inspect the radiator for leaks and clean the fins. Replace the thermostat if it's faulty. Check the coolant level and top it off as needed. If the water pump is suspected, you can check for coolant leaks from the weep hole or unusual noises.

4. Transmission and Drivetrain Issues:

The Xplorer 400's transmission is generally reliable, but problems can arise:

  • Slipping clutch: The clutch may slip under heavy load, causing a loss of power.
  • Worn drive belt: The drive belt transfers power from the engine to the transmission. A worn belt can slip or break.
  • Differential problems: The front and rear differentials can develop leaks or wear out, causing noise and poor performance.
  • Chain and sprocket wear: If your Xplorer has a chain drive, the chain and sprockets will eventually wear out and need to be replaced.

The Fix: Adjust the clutch cable if necessary. Replace the drive belt if it's worn or damaged. Check the differential fluid level and add fluid as needed. Inspect the chain and sprockets for wear and replace them as a set if necessary.

5. Suspension and Steering Woes:

A comfortable and safe ride depends on a healthy suspension and steering system:

  • Worn ball joints and tie rod ends: These components can wear out over time, causing loose steering and poor handling.
  • Leaking shocks: Shocks can lose their damping ability over time, resulting in a bouncy ride.
  • Worn wheel bearings: Wheel bearings can wear out, causing noise and wobble.

The Fix: Inspect the ball joints, tie rod ends, and wheel bearings for play. Replace them if they're worn. Rebuild or replace the shocks if they're leaking or not providing adequate damping.

Digging Deeper: Specific Xplorer 400 Quirks

Beyond the general mechanical issues, the Xplorer 400 has a few specific quirks to be aware of:

  • Oil Injection System: Some Xplorer 400 models use an oil injection system to lubricate the engine. This system can fail, leading to engine damage. Many owners choose to disable the oil injection system and mix oil directly into the fuel. Carefully research the proper oil-to-fuel ratio if you decide to do this.
  • Reverse Mechanism: The reverse mechanism on some Xplorer 400 models can be finicky and prone to problems. Make sure the cable is properly adjusted and lubricated.
  • Starter Issues: The starter motor can wear out over time, causing starting problems. Consider replacing the starter motor or rebuilding it.

Troubleshooting Like a Pro: A Step-by-Step Approach

When your Xplorer 400 throws you a curveball, don't panic! Here's a systematic approach to troubleshooting:

  1. Gather Information: What exactly is happening? When did the problem start? Are there any unusual noises, smells, or visual signs?
  2. Check the Basics: Is the fuel tank full? Is the battery charged? Are all the connections tight?
  3. Consult the Service Manual: A service manual is an invaluable resource for diagnosing and repairing your Xplorer 400.
  4. Use a Multimeter: A multimeter is an essential tool for diagnosing electrical problems.
  5. Don't Be Afraid to Ask for Help: If you're stuck, don't hesitate to ask for help from a qualified mechanic or online forum.

Preventing Problems: Maintenance is Key

The best way to deal with Xplorer 400 problems is to prevent them in the first place. Regular maintenance is crucial:

  • Change the oil regularly: Use the recommended oil type and change it according to the service manual.
  • Keep the air filter clean: A dirty air filter can restrict airflow and reduce engine performance.
  • Grease the chassis: Regularly grease the ball joints, tie rod ends, and other grease fittings.
  • Inspect the brakes: Check the brake pads and rotors for wear.
  • Store your Xplorer 400 properly: If you're not going to use your Xplorer 400 for an extended period, store it properly to prevent fuel from going stale and batteries from dying.

Frequently Asked Questions

  • Why is my Xplorer 400 hard to start? A hard starting Xplorer 400 is often caused by a clogged carburetor or a weak battery. Cleaning the carburetor and charging or replacing the battery are common solutions.
  • My Xplorer 400 is overheating. What should I do? Overheating can be caused by a low coolant level, a faulty thermostat, or a clogged radiator. Check these components and address any issues promptly.
  • How often should I change the oil in my Xplorer 400? Refer to your service manual for the recommended oil change interval, but generally, changing the oil every 50-100 hours of use is a good practice.
  • Can I still find parts for my Xplorer 400? Yes, parts for the Xplorer 400 are generally available, although some may be harder to find than others. Online retailers and salvage yards are good sources.
  • Is it worth fixing up an old Xplorer 400? That depends on the condition of the ATV and your budget. If the frame and engine are in good shape, it can be a worthwhile project, but be prepared to invest time and money.

Keeping Your Xplorer 400 Alive and Kicking

The Polaris Xplorer 400 is a tough and capable ATV that can provide years of reliable service with proper care and maintenance. By understanding the common problems and taking steps to prevent them, you can keep your Xplorer 400 running strong and enjoying its classic charm for years to come. Always consult your service manual for specific instructions and recommendations.