The Polaris Khaos 850, designed for aggressive backcountry riders, promises unparalleled agility and power. However, even the most meticulously engineered machines can face challenges. While the Khaos 850 delivers thrilling performance, some owners have reported experiencing a variety of issues, ranging from minor inconveniences to more significant mechanical concerns. Understanding these potential problems is crucial for prospective buyers and current owners alike, enabling informed decisions and proactive maintenance strategies.

So, What's the Buzz About Khaos 850 Issues?

It's no secret that the Polaris Khaos 850 has generated a lot of buzz since its release. Much of that buzz has been positive, highlighting its impressive power-to-weight ratio and exceptional maneuverability. But alongside the accolades, there's also been a growing conversation surrounding potential problems that some riders have encountered. Let's delve into some of the most commonly reported issues:

1. Engine Performance and Reliability:

  • Detonation/Pinging: One of the most frequently discussed issues is engine detonation, often referred to as "pinging." This occurs when the fuel-air mixture ignites prematurely in the cylinder, leading to a knocking or pinging sound. Detonation can cause serious engine damage over time, including piston failure and cylinder head damage. Several factors can contribute to detonation, including:
    • Poor Fuel Quality: Using low-octane fuel or fuel that has degraded over time can significantly increase the risk of detonation. Always use the recommended fuel grade specified by Polaris.
    • Lean Fuel Mixture: A lean fuel mixture (too much air, not enough fuel) can cause the engine to run hotter, increasing the likelihood of detonation. This can be caused by a malfunctioning fuel injector, a faulty fuel pump, or air leaks in the intake system.
    • High Engine Temperatures: Overheating can also contribute to detonation. Ensure the cooling system is functioning correctly and that the snowmobile is not being operated in conditions that could lead to overheating (e.g., deep snow with insufficient cooling).
  • Hard Starting: Some owners have reported difficulty starting their Khaos 850s, particularly in cold weather. This can be attributed to several factors, including:
    • Weak Battery: Cold temperatures can significantly reduce battery performance. Ensure the battery is fully charged and in good condition.
    • Fuel System Issues: Problems with the fuel pump, fuel filter, or fuel injectors can hinder fuel delivery, making starting difficult.
    • Incorrect Starting Procedure: Ensure you are following the correct starting procedure outlined in the owner's manual.
  • Engine Stalling: Occasionally, riders have experienced engine stalling, particularly at low speeds or idle. This can be caused by:
    • Idle Speed Adjustment: The idle speed may need to be adjusted to ensure the engine runs smoothly at low speeds.
    • Throttle Position Sensor (TPS) Issues: A malfunctioning TPS can send incorrect signals to the engine control unit (ECU), leading to stalling.
    • Fuel System Problems: Similar to hard starting, fuel system issues can also cause stalling.

2. Belt Issues:

The aggressive riding style the Khaos 850 encourages puts a significant strain on the drive belt. Premature belt wear and breakage are common complaints. Several factors contribute to this:

  • Clutch Alignment: Proper clutch alignment is crucial for belt longevity. Misalignment can cause excessive belt wear and heat buildup.
  • Clutch Calibration: Incorrect clutch calibration (e.g., wrong weights or springs) can also lead to belt problems. Ensure the clutches are properly calibrated for your riding style and altitude.
  • Riding Style: Aggressive riding, including frequent full-throttle starts and stops, can significantly shorten belt life.
  • Belt Quality: Using a high-quality, OEM-specified belt is essential for optimal performance and durability.

3. Suspension Concerns:

The Khaos suspension is designed for aggressive riding, but some riders have reported issues with its performance and durability:

  • Shock Performance: Some riders have found the stock shocks to be inadequate for their riding style, particularly in rough terrain. Upgrading to aftermarket shocks can significantly improve suspension performance.
  • Spring Sag: Over time, the springs can sag, leading to reduced ride height and bottoming out. Replacing the springs with heavier-duty options can address this issue.
  • Rear Suspension Linkage Wear: The rear suspension linkage can be prone to wear, particularly in harsh conditions. Regular lubrication and inspection are essential to prevent premature failure.

4. Electrical Gremlins:

Like any complex machine, the Khaos 850 can be susceptible to electrical problems:

  • Sensor Failures: Various sensors, such as the TPS, coolant temperature sensor, and exhaust temperature sensor, can fail, leading to engine performance issues and warning lights.
  • Wiring Issues: Loose or corroded connections can cause intermittent problems. Regularly inspect the wiring harness for damage and ensure all connections are secure.
  • ECU Problems: While less common, ECU problems can occur, leading to a wide range of issues.

5. Fit and Finish:

Some owners have expressed concerns about the fit and finish of certain components:

  • Panel Fitment: Gaps or misalignment in the body panels have been reported by some owners.
  • Component Durability: Some components, such as the handlebar grips and seat cover, may exhibit premature wear.

Digging Deeper: Addressing the Problems

Now that we've identified some of the common issues, let's explore potential solutions and preventative measures:

Engine Performance and Reliability:

  • Fuel Management:
    • Use Premium Fuel: Always use the recommended fuel grade specified by Polaris.
    • Fuel Stabilizer: Add fuel stabilizer to the fuel tank when storing the snowmobile for extended periods.
    • Fuel Filter Replacement: Regularly replace the fuel filter to ensure clean fuel delivery.
    • Check Fuel Lines: Inspect fuel lines for cracks or leaks.
  • Cooling System Maintenance:
    • Coolant Level: Check the coolant level regularly and top up as needed.
    • Coolant Flush: Flush the cooling system periodically to remove contaminants.
    • Inspect Radiator: Inspect the radiator for damage and ensure it is free of debris.
  • Engine Monitoring:
    • Exhaust Temperature Sensor (EGT) Monitoring: Consider installing an aftermarket EGT gauge to monitor exhaust temperatures and detect potential detonation issues.
    • Detonation Control: Some aftermarket ECUs offer detonation control features that can help prevent engine damage.

Belt Issues:

  • Clutch Maintenance:
    • Clutch Alignment: Regularly check and adjust clutch alignment.
    • Clutch Cleaning: Clean the clutches periodically to remove belt dust and debris.
    • Clutch Calibration: Ensure the clutches are properly calibrated for your riding style and altitude.
  • Belt Management:
    • Break-in Period: Follow the recommended belt break-in procedure.
    • Belt Inspection: Regularly inspect the belt for wear and damage.
    • Spare Belt: Carry a spare belt with you on rides.
  • Riding Technique:
    • Smooth Throttle Control: Avoid excessive full-throttle starts and stops.
    • Proper Warm-up: Allow the engine and clutches to warm up properly before engaging in aggressive riding.

Suspension Concerns:

  • Shock Upgrades: Consider upgrading to aftermarket shocks for improved performance and durability.
  • Spring Replacement: Replace worn or sagging springs with heavier-duty options.
  • Regular Lubrication: Lubricate the suspension linkage regularly to prevent wear.

Electrical Gremlins:

  • Wiring Inspection: Regularly inspect the wiring harness for damage and ensure all connections are secure.
  • Dielectric Grease: Apply dielectric grease to electrical connections to prevent corrosion.
  • Battery Maintenance: Maintain the battery in good condition and ensure it is fully charged.

Fit and Finish:

  • Panel Adjustment: Adjust the body panels as needed to improve fitment.
  • Component Replacement: Replace worn or damaged components as necessary.

Frequently Asked Questions

  • Why is my Khaos 850 detonating? Detonation can be caused by low-octane fuel, a lean fuel mixture, or high engine temperatures. Ensure you are using the correct fuel and that the cooling system is functioning properly.
  • What can I do to prevent belt failures on my Khaos 850? Proper clutch alignment, clutch calibration, and smooth throttle control are essential for preventing belt failures. Also, use a high-quality, OEM-specified belt.
  • Is it normal for the Khaos 850 to be hard to start in cold weather? Cold temperatures can affect battery performance and fuel delivery, making starting more difficult. Ensure the battery is fully charged and consider using a cold-weather starting aid.
  • Are aftermarket shocks worth the investment on a Khaos 850? If you ride aggressively or in rough terrain, upgrading to aftermarket shocks can significantly improve suspension performance and ride quality.
  • How often should I service my Khaos 850's clutches? It's recommended to service your clutches at least once a year, or more frequently if you ride in dusty or dirty conditions.

The Takeaway

While the Polaris Khaos 850 offers an exhilarating riding experience, being aware of potential problems is crucial for maintaining its performance and reliability. By understanding the common issues, implementing preventative measures, and performing regular maintenance, you can minimize downtime and maximize your enjoyment of this high-performance snowmobile. Addressing these potential issues head-on will allow you to enjoy the Khaos 850 as it was intended: tearing up the backcountry.