Kawasaki 900 Jet Ski Problems

The Kawasaki 900 Jet Ski, a legend of the 1990s, offered thrilling performance and cemented Kawasaki's reputation in the personal watercraft (PWC) market. However, like any machine of its age, the 900 series is prone to specific issues that owners often encounter. Understanding these potential problems, their causes, and effective solutions is crucial for keeping your classic Jet Ski running strong and enjoying its vintage charm for years to come.

So, You've Got a Kawasaki 900... What Could Go Wrong?

These skis are getting older, and time takes its toll. Let's dive into some common problems you might face with your Kawasaki 900.

Fuel System Foibles:

• Carburetor Clogs: This is probably the most frequent complaint. The carburetors on the 900 are susceptible to clogging from old fuel, debris, and varnish buildup. Symptoms include rough idling, hesitation during acceleration, and overall poor performance.
  • The Fix: Thorough carburetor cleaning is essential. This involves disassembling the carbs, soaking the components in carburetor cleaner, and using compressed air to clear out all passages. Replacing fuel lines and the fuel filter is also highly recommended. A good ultrasonic cleaner can work wonders here.
• Fuel Pump Issues: The fuel pump can weaken over time, leading to fuel starvation, especially at higher RPMs.
  • The Fix: Test the fuel pump's output pressure. If it's below specification, replace the pump.
• Fuel Tank Contamination: Rust, sediment, and old fuel can accumulate in the fuel tank, contaminating the entire fuel system.
  • The Fix: Drain and thoroughly clean the fuel tank. Consider using a fuel tank cleaner designed to remove rust and varnish. Inspect the fuel pickup and replace it if necessary.
• Rotting Fuel Lines: The ethanol in modern fuel degrades the rubber fuel lines on older machines, causing leaks and fuel delivery problems.
  • The Fix: Replace all fuel lines with ethanol-resistant (SAE J30R7 or better) fuel lines.

Engine Enigmas:

• Compression Loss: A common issue in older two-stroke engines. Low compression can result from worn piston rings, cylinder wear, or head gasket leaks.
  • The Fix: Perform a compression test on each cylinder. If compression is significantly lower than the manufacturer's specification, the engine likely needs a rebuild. This typically involves replacing the piston rings, honing or boring the cylinders, and potentially replacing the pistons.
• Overheating: Overheating can be caused by a blocked cooling system, a faulty thermostat, or a damaged impeller.
  • The Fix: Check the cooling system for blockages. Flush the system with fresh water and inspect the thermostat. If the thermostat is faulty, replace it. Inspect the impeller for damage and replace it if necessary. Also, ensure the water passages in the exhaust system are clear.
• Crankshaft Seal Leaks: The crankshaft seals prevent air from leaking into the crankcase, which is essential for proper engine operation. Worn or damaged seals can cause air leaks, leading to poor performance and difficult starting.
  • The Fix: Replace the crankshaft seals. This usually requires splitting the engine case.
• Ignition Coil Failure: The ignition coils provide the spark necessary to ignite the fuel mixture. A faulty ignition coil can cause misfires or a complete lack of spark.
  • The Fix: Test the ignition coils with a multimeter. If they are not within specification, replace them.

Electrical Gremlins:

• Battery Problems: A weak or dead battery is a common issue, especially if the Jet Ski has been sitting for a while.
  • The Fix: Charge the battery or replace it if it's no longer holding a charge. Consider using a battery tender to keep the battery charged during storage.
• Stator Issues: The stator generates electricity to charge the battery and power the ignition system. A faulty stator can cause charging problems or a lack of spark.
  • The Fix: Test the stator with a multimeter. If it's not producing the correct voltage, replace it.
• Wiring Harness Corrosion: Corrosion can build up in the wiring harness, causing electrical problems.
  • The Fix: Inspect the wiring harness for corrosion. Clean corroded connections with a wire brush and apply dielectric grease to prevent future corrosion. Replace damaged wires as needed.
• Starter Problems: The starter motor may fail, preventing the engine from starting.
  • The Fix: Test the starter motor. If it's not working, replace it. Also, check the starter relay and solenoid.

Hull and Driveline Headaches:

• Wear Ring Damage: The wear ring surrounds the impeller and helps to create a tight seal, maximizing thrust. A damaged wear ring can reduce performance.
  • The Fix: Inspect the wear ring for damage. If it's worn or cracked, replace it.
• Impeller Damage: The impeller can be damaged by debris or cavitation.
  • The Fix: Inspect the impeller for damage. If it's bent, chipped, or corroded, replace it.
• Jet Pump Seal Leaks: Leaks in the jet pump seals can reduce thrust and performance.
  • The Fix: Inspect the jet pump seals. If they are leaking, replace them.
• Hull Cracks and Leaks: Older hulls can develop cracks and leaks, especially in areas that are exposed to stress.
  • The Fix: Inspect the hull for cracks and leaks. Repair any damage with fiberglass or epoxy resin.

Exhaust System Exhaustion:

• Water Box Leaks: The water box helps to quiet the exhaust and cool the exhaust gases. Over time, the water box can corrode and develop leaks.
  • The Fix: Inspect the water box for leaks. Repair any leaks with epoxy resin or replace the water box.
• Exhaust Hose Degradation: The exhaust hoses can degrade over time, leading to leaks and exhaust fumes entering the engine compartment.
  • The Fix: Inspect the exhaust hoses for cracks and leaks. Replace any damaged hoses.

Keeping Your Kawasaki 900 Alive: Preventative Maintenance is Key

The best way to avoid these problems is through regular preventative maintenance. Here's a checklist to keep your Kawasaki 900 running smoothly:

• Regularly Inspect and Clean Carburetors: At least once a year, or more often if you notice any performance issues.
• Use Fuel Stabilizer: Add fuel stabilizer to the fuel tank whenever you're storing the Jet Ski for an extended period.
• Change Fuel Filter Regularly: Replace the fuel filter at least once a year.
• Inspect and Replace Fuel Lines: Check the fuel lines for cracks and leaks and replace them as needed.
• Grease Fittings: Regularly grease all grease fittings on the Jet Ski.
• Check and Adjust Cables: Check the throttle and steering cables for proper adjustment and lubrication.
• Inspect and Clean the Jet Pump: Inspect the impeller and wear ring for damage and clean the jet pump regularly.
• Flush the Cooling System: Flush the cooling system with fresh water after each use, especially if you've been riding in saltwater.
• Store the Jet Ski Properly: Store the Jet Ski in a dry, covered location when not in use.
• Winterize Properly: Follow proper winterization procedures before storing the Jet Ski for the winter. This includes fogging the engine, draining the cooling system, and disconnecting the battery.

Finding Parts and Resources

Finding parts for a Kawasaki 900 can be a challenge, but there are still resources available:

• Online Retailers: Many online retailers specialize in parts for older Jet Skis.
• eBay: eBay can be a good source for used and NOS (new old stock) parts.
• Jet Ski Forums: Jet Ski forums are a great place to connect with other owners and find parts and advice.
• Local Mechanics: Some local mechanics may specialize in working on older Jet Skis and have access to parts.

Frequently Asked Questions

• Why does my Kawasaki 900 bog down when I accelerate? This is often due to clogged carburetors. Clean or rebuild the carburetors to resolve this issue.

• My Jet Ski won't start. What could be the problem? Check the battery, spark plugs, and ignition system. A faulty starter or stator can also prevent starting.

• How often should I change the oil in my Kawasaki 900? The Kawasaki 900 is a two-stroke engine and doesn't have an oil pan like a four-stroke. You need to ensure you are topping off the oil reservoir with high-quality two-stroke oil.

• What type of fuel should I use in my Kawasaki 900? Use premium unleaded gasoline with an octane rating of 91 or higher. Adding a fuel stabilizer is also recommended.

• Where can I find a service manual for my Kawasaki 900? Service manuals can often be found online through various sources, either for purchase or as downloadable PDFs.

Conclusion

Owning a Kawasaki 900 Jet Ski is a rewarding experience, offering a taste of classic PWC performance. By understanding the common problems these machines face and practicing preventative maintenance, you can keep your 900 running strong and enjoy it for many years to come. Addressing issues promptly and staying proactive with maintenance will save you time and money in the long run.