The Suzuki RF900R, a sport-touring icon of the 1990s, offered a compelling blend of performance and comfort. However, like any machine of its age, the RF900R isn't without its quirks and potential problems. Understanding these issues is crucial for prospective buyers and current owners alike, allowing for informed decisions and proactive maintenance that can keep these classic bikes on the road for years to come. Let's dive into the common gremlins that can plague the RF900R and explore how to tackle them.

The RF900R's Engine: Powerhouse with Potential Pitfalls

The heart of the RF900R is its robust 893cc inline-four engine, derived from the GSX-R750. While generally reliable, several issues can arise over time:

  • Cam Chain Tensioner (CCT) Woes: The automatic cam chain tensioner is a frequent point of failure. It can become noisy, rattling at idle and low RPMs, indicating wear or malfunction. A failing CCT can lead to improper valve timing, resulting in reduced performance and potentially engine damage. Upgrading to a manual cam chain tensioner is a popular and often recommended solution. This allows for precise adjustment and eliminates the reliance on the sometimes-unreliable automatic unit. Regular inspection and adjustment of a manual CCT are essential.

  • Carburetor Complications: The RF900R uses Mikuni BDST38 carburetors. These can become gummed up, especially if the bike has been sitting for extended periods. Symptoms include rough idling, hesitation, and poor fuel economy. A thorough cleaning and rebuild of the carburetors is often necessary to restore optimal performance. This involves disassembling the carbs, cleaning all jets and passages, replacing worn parts like o-rings and needles, and properly synchronizing them.

  • Valve Clearance Issues: Like all engines, the RF900R's valve clearances require periodic inspection and adjustment. Over time, the valve clearances can drift out of specification, leading to decreased performance, increased engine noise, and potential valve damage. Following the manufacturer's recommended maintenance schedule for valve clearance checks is crucial for long engine life.

  • Fuel Petcock Problems: The vacuum-operated fuel petcock can sometimes fail, leading to fuel starvation or leaks. This is often due to a cracked or perished diaphragm. Replacing the fuel petcock or rebuilding it with a new diaphragm kit is a relatively straightforward repair.

  • Oil Leaks: Older engines are prone to oil leaks. Common areas for leaks on the RF900R include the valve cover gasket, oil pan gasket, and around the oil cooler lines. Replacing these gaskets is typically a simple solution, but it's important to identify the source of the leak accurately.

Suspension and Handling: Maintaining the Sport-Touring Edge

The RF900R's suspension, while decent for its time, can suffer from wear and tear over the years:

  • Fork Seal Leaks: A common issue on older motorcycles is leaky fork seals. This results in reduced damping performance and can lead to oil contamination of the brake calipers. Replacing the fork seals is a necessary repair, and it's often recommended to replace the fork oil at the same time. Consider upgrading to heavier fork oil for improved handling.

  • Rear Shock Fade: The original rear shock can become tired and lose its damping ability over time. This can result in a bouncy ride and reduced handling performance. Replacing the rear shock with a new or rebuilt unit is a significant improvement. Aftermarket options often offer adjustable damping and preload, allowing for fine-tuning of the suspension.

  • Worn Steering Head Bearings: Worn steering head bearings can cause vague steering and instability, especially at higher speeds. Replacing the steering head bearings is a relatively involved but essential repair for restoring proper handling.

  • Swingarm Bearings: Check the swingarm bearings for play. Worn swingarm bearings can affect handling and stability. Replacing these bearings can significantly improve the bike's feel.

Electrical Gremlins: Taming the Electrons

The RF900R's electrical system, while generally reliable, can present some challenges:

  • Charging System Issues: The charging system, consisting of the stator, regulator/rectifier, and battery, can be a source of problems. A failing stator or regulator/rectifier can lead to a dead battery and prevent the bike from starting. Regularly check the charging system voltage to identify potential issues early on. Replacing faulty components with aftermarket upgrades is a common solution.

  • Wiring Harness Degradation: Over time, the wiring harness can become brittle and corroded, leading to intermittent electrical problems. Carefully inspect the wiring harness for damage and repair any frayed or corroded wires. Applying dielectric grease to electrical connections can help prevent corrosion.

  • Starter Relay Problems: The starter relay can sometimes fail, preventing the bike from starting. Replacing the starter relay is a relatively inexpensive and straightforward repair.

  • Grounding Issues: Poor grounding can cause a variety of electrical problems. Ensure that all grounding points are clean and secure.

Brakes: Keeping You Safe

The RF900R's brakes are adequate, but require attention to maintain optimal performance:

  • Brake Caliper Seizures: The brake calipers can become seized due to corrosion and dirt buildup. This results in reduced braking performance and uneven pad wear. Regularly cleaning and lubricating the brake calipers is essential for maintaining proper braking function. Rebuilding the calipers with new seals and pistons may be necessary.

  • Brake Line Degradation: The rubber brake lines can degrade over time, leading to spongy brake feel and reduced braking performance. Replacing the rubber brake lines with stainless steel braided lines is a worthwhile upgrade that improves brake feel and performance.

  • Master Cylinder Issues: The master cylinders can develop internal leaks, resulting in a soft brake lever or pedal. Rebuilding the master cylinders with new seals is a common repair.

Bodywork and Cosmetics: Preserving the Classic Look

While not directly affecting performance, maintaining the RF900R's bodywork is important for preserving its aesthetic appeal:

  • Cracked Fairings: The fairings can be prone to cracking, especially around mounting points. Repairing cracked fairings with plastic welding or fiberglass repair is a common solution.

  • Faded Paint: The paint can fade over time due to exposure to the sun and elements. A fresh coat of paint can restore the bike's original luster.

  • Seat Deterioration: The seat can become torn or cracked over time. Reupholstering the seat is a relatively inexpensive way to improve the bike's comfort and appearance.

Specific RF900R Quirks and Oddities

Beyond the common issues, some quirks are specific to the RF900R:

  • The "RF Buzz": Many RF900R owners report a noticeable buzz or vibration at certain RPMs. This is often attributed to the engine mounting or fairing resonance. While not necessarily a problem, it can be annoying. Experimenting with different engine mounting techniques or adding dampening material to the fairings can sometimes reduce the buzz.

  • Coolant Leaks from the Water Pump: The water pump can be a source of coolant leaks. Replacing the water pump or its seals is a common repair.

  • Difficult Cold Starts: Some RF900Rs can be difficult to start when cold. This can be due to a variety of factors, including carburetor issues, weak battery, or low compression. Ensuring the carburetors are properly tuned and the battery is in good condition can often improve cold starting.

Frequently Asked Questions

  • Why is my RF900R making a rattling noise at idle? This is likely due to a failing cam chain tensioner. Consider upgrading to a manual CCT.

  • My RF900R is hard to start. What could be the problem? Possible causes include a weak battery, dirty carburetors, or low compression. Check these components.

  • Are parts readily available for the RF900R? Some parts are becoming harder to find, but many aftermarket options are available, and online communities can be a valuable resource.

  • Is the RF900R a reliable bike? Generally, yes, but like any older motorcycle, it requires regular maintenance and attention to potential problem areas.

  • How often should I change the oil on my RF900R? Every 3,000 miles or annually, whichever comes first, using a high-quality motorcycle-specific oil.

Keeping Your RF900R Alive and Kicking

Owning a Suzuki RF900R is a rewarding experience, offering a blend of classic style, comfortable touring, and respectable performance. By understanding the common problems and addressing them proactively, you can keep these iconic bikes on the road for many years to come. Prioritize regular maintenance and don't hesitate to seek advice from experienced RF900R owners or qualified mechanics.