The Arctic Cat 858 twin-cylinder engine, introduced in recent snowmobile models, promised a potent blend of power and performance. However, like any new engine design, it hasn't been without its teething issues. Understanding these potential problems, whether you're considering buying a sled with this engine or already own one, is crucial for ensuring a long and enjoyable riding experience. Let’s dive into the common concerns that have surfaced around the Arctic Cat 858, and what you can do to address them.

Decoding the Buzz: What's Everyone Talking About?

Before we get granular, let's clarify what kind of issues are popping up in the snowmobile community. Generally, the concerns center around engine reliability, fuel delivery, and some electronic quirks. These aren't necessarily universal problems affecting every 858 engine, but they are definitely recurring themes in online forums and repair shops. Knowing these potential pitfalls allows you to be proactive with maintenance and spot warning signs early.

Fuel Delivery Fumbles: Is Your 858 Starving?

One of the most frequently reported issues with the Arctic Cat 858 revolves around fuel delivery. This can manifest in several ways, impacting performance and potentially leading to engine damage.

  • Fuel Pump Issues: Some owners have reported issues with the fuel pump's ability to consistently deliver the required fuel pressure, especially under high-demand situations like wide-open throttle or sustained hill climbs. This can lead to lean running conditions, which can cause detonation and engine damage. Upgrading the fuel pump with a higher-capacity aftermarket unit is a common solution.
  • Fuel Injector Problems: The fuel injectors themselves can also be a source of trouble. Injector failure, either partial or complete, can disrupt the fuel-air mixture, leading to misfires, poor performance, and potential engine damage. Regular injector cleaning and inspection are essential preventative measures.
  • Fuel Filter Clogging: A dirty fuel filter restricts fuel flow, mimicking the symptoms of a weak fuel pump. Regularly replacing the fuel filter, especially after the initial break-in period, is crucial for maintaining optimal fuel delivery. Consider using a high-quality filter designed to handle the specific requirements of the 858 engine.
  • Fuel Line Issues: Check for kinks, cracks, or leaks in the fuel lines. Ethanol-blended fuels can degrade rubber fuel lines over time, leading to fuel leaks and inconsistent fuel pressure. Replacing the stock fuel lines with ethanol-resistant lines is a worthwhile investment.

Engine Woes: Addressing the Heart of the Matter

The engine itself, while generally robust, isn't immune to problems. Some key areas of concern include:

  • Piston Issues: Some early models experienced issues with piston durability, particularly under sustained high-performance conditions. This often manifested as piston skirt cracking or failure, leading to significant engine damage. Consider upgrading to forged pistons, which are stronger and more resistant to heat and stress, especially if you ride aggressively or frequently modify your sled.
  • Cylinder Head Leaks: Head gasket leaks can occur, leading to a loss of compression and coolant leakage. Regularly inspecting the cylinder head for signs of leakage, such as coolant stains or bubbling, is crucial. Retorquing the head bolts to the manufacturer's specifications can sometimes resolve minor leaks.
  • Detonation: As mentioned earlier, lean running conditions caused by fuel delivery problems can lead to detonation. Detonation is an uncontrolled explosion of the air-fuel mixture in the cylinder, which can cause severe damage to the pistons, cylinder head, and connecting rods. Using high-octane fuel and ensuring proper fuel delivery are essential for preventing detonation.
  • Oil Pump Issues: While less common, some reports have surfaced regarding oil pump malfunctions, leading to insufficient lubrication and potential engine damage. Regular inspection of the oil pump and ensuring the oil reservoir is properly filled are important preventative measures.

Electrical Gremlins: Taming the Tech

Modern snowmobiles rely heavily on electronic systems, and the Arctic Cat 858 is no exception. Electrical issues can be frustrating to diagnose and resolve.

  • Sensor Failures: Various sensors, such as the throttle position sensor (TPS), coolant temperature sensor, and exhaust gas temperature (EGT) sensor, play crucial roles in engine management. Sensor failures can lead to incorrect readings, causing the engine to run poorly or even shut down. Regular diagnostic checks and sensor replacement when necessary are important.
  • Wiring Harness Problems: The wiring harness can be vulnerable to damage from vibration, moisture, and abrasion. Chafed or broken wires can cause intermittent electrical problems and sensor malfunctions. Carefully inspect the wiring harness for any signs of damage and repair or replace damaged sections as needed.
  • ECU (Engine Control Unit) Glitches: While rare, the ECU itself can sometimes experience glitches or programming errors. This can lead to a variety of performance issues, including poor fuel economy, erratic throttle response, and even engine failure. Consider consulting with a qualified technician to reflash or reprogram the ECU if you suspect a problem.

Beyond the Engine: Other Potential Problem Areas

While the engine and electrical systems receive the most attention, other areas can also present challenges.

  • Clutch Issues: Clutch performance is critical for transferring power from the engine to the track. Worn or misadjusted clutches can lead to poor acceleration, belt slippage, and reduced top speed. Regular clutch maintenance, including cleaning, inspection, and proper adjustment, is essential for optimal performance.
  • Suspension Problems: The suspension system absorbs bumps and provides a comfortable ride. Worn shocks, broken springs, or damaged control arms can compromise handling and ride quality. Regularly inspect the suspension components for any signs of damage and replace worn parts as needed.
  • Exhaust System Issues: The exhaust system plays a crucial role in engine performance and emissions. Leaks in the exhaust system can reduce power and increase noise. Cracks or corrosion in the exhaust system should be repaired or replaced promptly.

Proactive Prevention: Keeping Your 858 Happy

The best way to deal with Arctic Cat 858 problems is to prevent them from happening in the first place. Here's a checklist of preventative measures:

  • Follow the Manufacturer's Recommended Maintenance Schedule: Adhering to the recommended maintenance schedule is crucial for ensuring the longevity and reliability of your engine. This includes regular oil changes, filter replacements, and inspections.
  • Use High-Quality Fuel and Oil: Using high-quality fuel with the correct octane rating and a premium synthetic oil designed for snowmobiles can significantly reduce the risk of engine problems.
  • Warm Up Your Engine Properly: Allow your engine to warm up fully before engaging in aggressive riding. This allows the oil to circulate properly and lubricate all engine components.
  • Avoid Sustained High-RPM Riding: While the 858 engine is capable of high performance, sustained high-RPM riding can put excessive stress on engine components. Vary your riding style and avoid prolonged periods of wide-open throttle.
  • Regularly Inspect Your Sled: Take the time to regularly inspect your sled for any signs of damage or wear. This includes checking the fuel lines, wiring harness, suspension components, and exhaust system.
  • Store Your Sled Properly: Proper storage is essential for preventing corrosion and other damage during the off-season. Drain the fuel tank, stabilize the fuel, and lubricate the engine cylinders before storing your sled.

Frequently Asked Questions

  • Is the Arctic Cat 858 engine reliable? While it has some known issues, with proper maintenance and preventative measures, it can be reliable. Addressing potential problems early is key.
  • What are the most common problems with the 858 engine? Fuel delivery issues, piston problems, and electrical gremlins are the most frequently reported concerns.
  • Should I upgrade the fuel pump on my 858? If you ride aggressively or experience fuel delivery problems, upgrading the fuel pump is a worthwhile investment. It provides a higher fuel pressure.
  • What kind of fuel should I use in my 858? Always use high-octane fuel, especially when riding aggressively or in high-altitude conditions. This helps prevent detonation.
  • How often should I change the oil in my 858? Follow the manufacturer's recommended oil change interval, or more frequently if you ride in harsh conditions. Regular oil changes are crucial for engine longevity.

Conclusion

While the Arctic Cat 858 engine has presented some challenges, understanding these potential issues and implementing preventative measures can significantly improve its reliability and longevity. By staying informed, being proactive with maintenance, and addressing problems early, you can enjoy the powerful performance of this engine for years to come.