The Suzuki Boulevard C90, a classic cruiser known for its comfortable ride and reliable engine, has won the hearts of many riders. However, like any motorcycle, it's not without its quirks and potential problems. Understanding these common issues can help you make an informed decision before purchasing, maintain your C90 effectively, and troubleshoot problems if they arise, ensuring many years of enjoyable riding. This guide delves into some of the most frequently reported Suzuki Boulevard C90 problems, offering insights and potential solutions to keep you on the road.

So, What are the Most Common C90 Issues?

While the C90 is generally considered a dependable machine, a few gremlins tend to surface more often than others. These aren’t necessarily deal-breakers, but being aware of them empowers you to address them proactively.

Fuel Injection Woes: The fuel injection system, while designed for efficiency and smooth running, can sometimes be a source of frustration.

Clutch Concerns: Clutch slippage and related issues are frequently mentioned by C90 owners.

Electrical Quirks: Like many bikes, the C90 can experience occasional electrical problems.

Rear Cylinder Heat: The rear cylinder's proximity to the rider can cause discomfort, especially in hot weather.

Let’s dig into each of these areas in more detail.

Fuel Injection Frustrations: Is Your C90 Running Rough?

The Suzuki Boulevard C90 utilizes a fuel injection system to deliver fuel to the engine more efficiently than a carburetor. This system relies on sensors, injectors, and a computer (ECU) to precisely control the air-fuel mixture. However, problems can arise, leading to rough idling, poor acceleration, and even stalling.

Common Culprits:

  • Throttle Position Sensor (TPS) Issues: The TPS tells the ECU the position of the throttle. If it's faulty, the ECU receives incorrect information, leading to improper fuel delivery. Symptoms include hesitation, jerky throttle response, and difficulty maintaining a steady speed. A multimeter can be used to test the TPS output voltage. If the voltage is outside the specified range (refer to your service manual), replacement is usually necessary.

  • Fuel Injector Problems: Injectors can become clogged over time with fuel deposits, restricting fuel flow. This results in lean running, misfires, and reduced power. Fuel injector cleaner added to the fuel tank can sometimes help, but in severe cases, cleaning or replacement is required. Ultrasonic cleaning is an effective method for restoring clogged injectors.

  • Vacuum Leaks: Leaks in the intake system can disrupt the air-fuel mixture, causing lean running conditions. Check all vacuum hoses and intake manifolds for cracks or loose connections. Using a spray bottle with soapy water to check for leaks around the intake manifold is a common diagnostic technique.

  • Fuel Pump Problems: A failing fuel pump can't deliver enough fuel to the injectors, leading to poor performance, especially at higher speeds. You can test the fuel pump pressure with a fuel pressure gauge. If the pressure is below the manufacturer's specification, the fuel pump needs to be replaced.

  • ECU (Engine Control Unit) Issues: While less common, the ECU itself can sometimes be the problem. This is usually diagnosed after ruling out other possibilities. A professional motorcycle mechanic with diagnostic tools is often required to assess ECU functionality.

Troubleshooting Tips:

  • Start with the easiest checks: Ensure you're using fresh fuel and that the fuel filter isn't clogged.
  • Listen for unusual noises from the fuel pump.
  • Visually inspect all vacuum lines and connections.
  • Consider using a fuel injector cleaner as a preventative measure.
  • If the problem persists, consult a qualified mechanic for a proper diagnosis.

Clutch Conundrums: Slipping and Sticking

Clutch problems are another relatively common complaint among C90 riders. These issues can range from minor annoyances to serious performance limitations.

What's Going On?

  • Clutch Slippage: This occurs when the clutch plates fail to fully engage, causing the engine to rev without transferring power to the rear wheel. This is often most noticeable under heavy acceleration or when climbing hills. Worn clutch plates are the most common cause.

  • Clutch Sticking: This happens when the clutch plates stick together, making it difficult to shift gears or find neutral. This can be caused by old or contaminated oil, or by warped clutch plates.

  • Clutch Cable Issues: A stretched or improperly adjusted clutch cable can also cause shifting problems.

Possible Solutions:

  • Adjust Clutch Cable: Ensure the clutch cable has the correct amount of free play. Refer to your service manual for the proper adjustment procedure. This is often the first and easiest step to take.

  • Change Engine Oil: Use the correct type and viscosity of oil recommended by Suzuki. Old or incorrect oil can contribute to clutch slippage and sticking. Ensure the oil level is correct.

  • Replace Clutch Plates: If the clutch plates are worn, they need to be replaced. This is a more involved repair but is often necessary to resolve slippage issues. Consider replacing the clutch springs at the same time for optimal performance.

  • Inspect Clutch Basket and Hub: Check the clutch basket and hub for grooves or damage. These can prevent the clutch plates from engaging properly. If damage is found, replacement might be needed.

  • Bleed Clutch Hydraulic System (If Applicable): Some C90 models have a hydraulic clutch system. Ensure the system is properly bled to remove any air bubbles.

Electrical Enigmas: Dealing with Gremlins in the Wiring

Electrical problems can be particularly frustrating because they can be difficult to diagnose. The C90, like any motorcycle, has a complex electrical system, and issues can arise from various sources.

Common Electrical Issues:

  • Battery Problems: A weak or failing battery is a common cause of electrical problems. Test the battery voltage and charging system. A load test can determine the battery's ability to hold a charge under load.

  • Charging System Issues: Problems with the stator, regulator/rectifier, or wiring can prevent the battery from charging properly. Use a multimeter to test the stator output voltage and the regulator/rectifier output voltage. Refer to your service manual for the correct testing procedures.

  • Wiring Harness Issues: Damaged or corroded wiring can cause a variety of problems, including intermittent failures, short circuits, and blown fuses. Visually inspect the wiring harness for any signs of damage. Check for corrosion at connectors.

  • Sensor Failures: Sensors, such as the crankshaft position sensor or the side stand switch, can fail and cause the engine to not start or run properly. Diagnostic codes can often help identify faulty sensors.

  • Fuse Problems: Blown fuses are often a symptom of a larger problem. Replace blown fuses with the correct amperage rating. If the fuse blows again immediately, there's likely a short circuit.

Troubleshooting Tips:

  • Start by checking the battery voltage and connections.
  • Inspect all fuses for damage.
  • Look for any signs of corrosion or damage to the wiring harness.
  • Use a multimeter to test the charging system and individual components.
  • Consult a wiring diagram to trace circuits and identify potential problems.
  • Consider using dielectric grease on electrical connectors to prevent corrosion.

Rear Cylinder Heat: Feeling the Burn?

The C90's rear cylinder is located close to the rider's leg, which can lead to discomfort, especially in hot weather. This is a common complaint among C90 owners, and while it's not necessarily a mechanical problem, it's something to be aware of.

Why the Heat?

The rear cylinder receives less airflow than the front cylinder, causing it to run hotter. This heat is then radiated towards the rider's leg.

Possible Mitigation Strategies:

  • Riding Style: Avoid prolonged idling in hot weather. Keep the bike moving to allow for better airflow.

  • Aftermarket Heat Shields: Several aftermarket heat shields are available that can deflect heat away from the rider's leg. These are a popular solution for many C90 owners.

  • Ceramic Coating: Coating the exhaust pipes with a ceramic coating can help reduce heat radiation.

  • Fuel Mixture Adjustments: Ensuring the engine is running with the correct air-fuel mixture can also help reduce heat. A lean running condition can cause the engine to run hotter.

  • Proper Engine Maintenance: Regular maintenance, including oil changes and spark plug replacement, can help ensure the engine is running efficiently and not generating excessive heat.

Frequently Asked Questions About C90 Problems

  • Why is my C90 stalling at idle? This could be due to a faulty throttle position sensor, clogged fuel injectors, or vacuum leaks. Inspect these components and consider using fuel injector cleaner.

  • My clutch is slipping, what should I do? First, adjust the clutch cable. If the problem persists, you may need to replace the clutch plates.

  • What kind of oil should I use in my C90? Refer to your owner's manual for the recommended oil type and viscosity. Using the wrong oil can lead to clutch problems and engine damage.

  • My battery keeps dying, what's the problem? This could be a sign of a failing battery or a problem with the charging system. Have the battery and charging system tested.

  • How can I reduce the heat from the rear cylinder? Consider installing aftermarket heat shields or having the exhaust pipes ceramic coated. Adjusting the fuel mixture can also help.

Keeping Your Boulevard Rolling

The Suzuki Boulevard C90, while generally a reliable machine, can experience its share of common problems. By being aware of these potential issues and taking proactive steps to maintain your motorcycle, you can minimize the risk of breakdowns and enjoy many miles of smooth, comfortable riding. Remember, regular maintenance and prompt attention to any unusual symptoms are key to keeping your C90 in top condition.