Yamaha Grizzly 700: Unravelling Common Issues

The Yamaha Grizzly 700 has long been celebrated as a robust and dependable quad, engineered to tackle the most demanding terrains and aggressive riding styles with its resilient frame. Its reputation for durability is well-earned, making it a favourite among off-road enthusiasts across the UK. However, like any complex piece of machinery, the Grizzly 700 isn't entirely without its quirks. Many owners, despite their affection for the machine, have encountered a range of issues that, while often resolvable, can certainly test one's patience. Understanding these common problems is key to effective maintenance and ensuring your Grizzly remains a reliable companion on every adventure.

From minor annoyances to more significant mechanical concerns, these issues, including the often-discussed spongy rear brakes, can sometimes lead an owner to question their purchase. Thankfully, most of these challenges can be addressed through straightforward adjustments, diligent maintenance, or, in more complex cases, a quick call to your authorised Yamaha dealer. This article delves into the most prevalent Yamaha Grizzly 700 problems, offering insights into their causes and practical solutions to help you keep your quad in peak condition.

Spongy Rear Brakes: A Common Gripe?

One particular issue that frequently surfaces in discussions among Yamaha Grizzly 700 owners is the sensation of spongy rear brakes, especially after new brake pads have been installed. This can be a rather disconcerting feeling, as it directly impacts your confidence and control, particularly when navigating challenging terrain. While the braking system of the Yamaha Grizzly is generally considered robust and reliable, this specific problem is almost invariably linked to the bleeding process following a brake pad replacement.

The primary culprit behind a spongy brake pedal is air trapped within the hydraulic brake lines. When new brake pads are fitted, it’s absolutely crucial to perform a thorough and complete brake bleed. If air is left in the system, it compresses when you apply the brakes, leading to that characteristic soft, yielding feel rather than a firm, responsive pedal. This means that the hydraulic pressure isn't being efficiently transferred to the brake callipers, significantly reducing braking effectiveness. To rectify this, a complete and meticulous bleeding of the brake system is required. Owners have found success using a power bleeder, which can create a vacuum or pressure to draw fluid through the system, or even a simple turkey baster for a more manual, albeit effective, approach. It is paramount to use the correct fluid type, specifically DOT 4 fluid, for this procedure to ensure compatibility and optimal performance of your Grizzly's braking system. Proper bleeding ensures all air is expelled, restoring the firm, reliable brake feel you need for safe riding.

Other Noteworthy Yamaha Grizzly 700 Issues

Beyond the brakes, Grizzly owners have reported a variety of other common issues:

Stability Concerns on Challenging Terrain

Many Grizzly owners have noted that the quad can feel somewhat unstable, particularly when traversing steep hills or cornering at speed. This characteristic is largely attributed to the Grizzly 700's design philosophy. Built with a lightweight chassis to ensure superior handling and agility over various obstacles, its compact dimensions and relatively high seating position can contribute to a perception of instability. While this design aids in manoeuvrability, it's something riders need to be aware of and adjust their riding style for, especially on uneven or sloped surfaces.

Engine Noise and Overheating Woes

The Yamaha Grizzly 700, featuring a single-cylinder engine, is sometimes criticised for generating more noise compared to its two-cylinder counterparts. This design, while efficient, can also lead to issues with overheating if not properly managed, especially during prolonged or strenuous use. If you notice your Grizzly's engine running hotter than usual, or if the noise becomes excessive, considering the addition of an auxiliary radiator can significantly improve cooling efficiency. For noise reduction, some owners have successfully fitted an additional muffler to the rear rack, helping to dampen the engine's exhaust note.

Air Filter Vulnerabilities

A recurring complaint among some owners concerns the air filter's susceptibility to ingress from dust, sand, and other fine debris. This seemingly minor issue can have serious long-term consequences, as these abrasive particles can find their way into vital internal engine components such as valves, pistons, and cylinder walls. Over time, this can lead to accelerated wear, excessive oil consumption, diminished engine performance, and, in severe cases, outright engine failure. To mitigate this, it's recommended to apply a generous layer of filter grease around the outer edges of the air filter before securely seating it. Furthermore, if you frequently ride in particularly dusty environments, more frequent inspections and cleaning of the airbox are essential.

Startup Troubles: Smoke and Non-Starts

A concerning issue, particularly noted in some 2016 Yamaha Grizzly 700 models, involves the quad smoking on startup. This is often indicative of underlying valve issues within the engine. For accurate diagnosis and resolution, it is highly advisable to consult an authorised Yamaha dealer. Alternatively, a knowledgeable mechanic can perform an engine valve clearance check to determine if adjustments are required. Separately, general starting problems are common across various Grizzly 700 year models. These can stem from a compression spring that has become dislodged or valves that are excessively tight and require adjustment. In instances where the quad won't start, particularly with models equipped with auto EPS, the issue might be electrical. Troubleshooting this requires a set of specific tools, including 10- and 12-mm sockets, a 4 mm Allen key, a Phillips screwdriver, a Volt/OHM meter capable of testing diodes, and a test lead kit. Always refer to your owner's manual for detailed wiring diagrams and diagnostic procedures.

Fuel System Quirks

Upon removing the gas cap on some Yamaha Grizzly 700 models, owners might encounter a distinct, loud hiss. This sound is a tell-tale sign of a defective gas tank rollover valve that isn't venting correctly. This was a known issue in earlier models, which Yamaha subsequently addressed with an updated rollover valve design. If you experience this, contacting your dealership for a replacement is the recommended course of action. Another fuel-related problem involves the engine backfiring and then dying, sometimes even on quads with very low mileage. Symptoms include the quad dying at idle (whether in gear or not), periodic backfiring, extreme pressure in the fuel tank, and power issues under load. Potential causes for this include contaminated fuel, a worn-out spark plug, a fuel-starved engine, or a faulty fuel pump, all of which disrupt the precise fuel-air mixture required for optimal engine operation.

Mysterious Clanking Noises

A disconcerting clanking noise, particularly when engaging 2WD or 4WD, has been reported by some owners, often occurring after aggressive acceleration. Initial suspicions might point towards a snapped axle, and indeed, issues with bearings and axles can be the cause, particularly in modified ATVs. However, owners have often traced this noise back to either a faulty transmission or differential. To accurately pinpoint the source of the clanking, a diagnostic step involves disconnecting the driveshaft, which can help isolate the problem area.

Lagging Acceleration

Poor acceleration is another complaint that can significantly impact the riding experience. This issue is frequently linked to the Yamaha Grizzly 700's air filter design, which, if compromised, can effectively starve the engine of sufficient air. A clogged air filter prevents an adequate volume of air from reaching the engine's intake or combustion chamber, leading to an overly rich air-fuel mixture. This imbalance can result in sluggish performance and, in some cases, an engine that runs erratically due to an improper combustion process. Regular inspection and cleaning or replacement of the air filter are vital to ensure optimal engine breathing and responsive acceleration.

The Cold Start Conundrum

Owners of 2016 and more recent Yamaha Grizzly models have sometimes reported difficulty in cold-starting, despite the electrical starting system functioning correctly. The engine may struggle to turn over, particularly in colder temperatures. This specific problem was traced to a broken decompression spring, which could become weakened during the manufacturing process. Yamaha acknowledged this issue in July 2016 and issued a recall for affected Grizzly and Kodiak units, advising owners to contact their Yamaha dealer to have the defective part replaced with a higher-quality decompression spring, ensuring reliable cold starts.

Steering Control Anomalies

While largely an anecdotal issue specific to certain model years, Yamaha Grizzly power steering problems were noted in 2008, 2009, and 2010 models. These issues, caused by a defect in the steering column support assembly, posed a significant crash hazard, potentially leading to riders losing control. This led to a recall of 20,000 units of 700- and 550-class Grizzlys and unfortunately, hundreds of rollover accident lawsuits. Thankfully, this was a resolved issue, not typically seen in newer models, but highlights the importance of addressing safety-critical defects promptly.

Diagnosing and Preventing Grizzly 700 Problems

Identifying common issues is one thing, but knowing how to diagnose and prevent them is equally important for any Grizzly owner. Proactive maintenance can save you a lot of hassle and expense.

Electrical System Checks

When troubleshooting startup problems, especially with older models like the 2008 Yamaha Grizzly 700, the first step is always to verify the battery's health. Ensure your battery registers 12.5V or higher; anything below this indicates a potentially unhealthy battery that might require replacement. A battery tender is an excellent investment for prolonging battery life by monitoring and charging it as needed. Furthermore, check that the starter solenoid fires up. Using a test lead kit to inspect if the starter solenoid responds after contact with its two terminals can help rule it out as the cause of your starting problem. If it functions correctly, you'll need to investigate other components such as the relay assembly, brake light relay, diode assembly, run switch connector, engine start switch, and reverse switch.

Engine Health: Oil and Cooling

Regularly inspect your engine oil for any signs of water contamination, which often leads to bearing wear and denatured oil, causing severe damage to the engine and its cooling system. This is a leading cause of smoke during startup or engine stalling. Equally important is ensuring the oil level is always according to specification. An incorrect or low oil level, though uncommon, can cause the stator to overheat, a symptom sometimes confused with a bad battery. If overheating occurs, check the oil level and stator condition before replacing the battery. If the stator is the culprit, replace it and consider pairing it with an updated stator cover. Finally, regularly check the radiator for bent fins. Bent fins significantly decrease the heat exchange efficiency, leading to suboptimal cooling, especially in high ambient temperatures. Keeping your radiator clean, particularly after muddy rides, is crucial for optimal cooling system performance.

Chassis and Drivetrain Inspection

Periodically inspect bearings and tie rods for noticeable dents and cracks. This includes checking the wheel bearings and knuckle bushings for wear and tear, as these are often responsible for popping or clanking noises. Frequent greasing of these parts can significantly slow down their deterioration. Also, conduct a thorough check of the power steering system by fully turning your Grizzly left and right. Any resistance encountered could indicate a defect with the torque sensor, spline column, speed sensor, or the EPS control unit itself.

Regular Maintenance Essentials

Regular inspection of your air filter is paramount. Older Grizzly models particularly benefit from frequent checks to prevent poor engine performance and throttle response due to clogging. Newer models (2015 onwards) feature an improved high-flow air filter system and optimised intake joint, reducing clogging issues. Its high placement under the seat also better prevents water, mud, and particles from causing internal problems. Lastly, ensure all nuts and bolts are sufficiently tight. This includes lug nuts, pivot bolts, axle nuts, wheel hubs, skid plate bolts, and sprocket bolts. A loose bolt can lead to a cascade of problems and compromise safety. When riding, pay attention to any loud whining noises when you let off the throttle at higher RPMs; this could indicate a one-way bearing installed backward or incorrectly, or a worn-out primary shaft support bearing. Finally, always test your brakes after installing new pads to ensure neither the front nor rear brakes feel spongy. If they do, a full bleed is necessary to resolve the issue.

Common Yamaha Grizzly 700 Problems & Solutions

Here's a quick reference for some of the most common issues and their typical resolutions:

• Unstable on Hills/Corners: Often due to lightweight design; adjust riding style.
• Engine Noisy/Overheats: Single-cylinder design; consider adding a radiator or secondary muffler.
• Dust/Dirt Through Filter: Apply filter grease; inspect airbox more frequently in dusty conditions.
• Smokes on Startup: Valve issues; consult a Yamaha dealer or check valve clearance.
• Won't Start: Compression spring, tight valves, electrical; diagnose with specific tools (volt/ohm meter, test leads).
• Defective Gas Tank Rollover Valve: Loud hiss when removing cap; contact dealership for updated replacement.
• Engine Backfires/Dies: Contaminated fuel, worn spark plug, fuel pump issues; diagnose and address fuel system components.
• Clanking Noise (2WD/4WD): Snapped axle, bearings, transmission/differential; disconnect driveshaft for diagnosis.
• Rear Brakes Spongy (New Pads): Incomplete brake bleed; use power bleeder or turkey baster with DOT 4 fluid.
• Poor Acceleration: Clogged air filter, rich mixture; regular air filter inspection/replacement.
• Difficult Cold-Weather Starting: Broken decompression spring (2016+ models); recall for replacement at dealer.
• Steering Control Problems: Defective steering column (2008-2010 models); addressed by recall.

Frequently Asked Questions (FAQs)

Q: Why do my Yamaha Grizzly 700 rear brakes feel spongy after changing pads?
A: This is almost always due to air trapped in the hydraulic brake lines. A full and proper bleeding of the brake system is required to expel the air, using DOT 4 fluid.

Q: My Grizzly 700 engine seems very noisy and overheats. What can I do?
A: The single-cylinder design can contribute to noise. For overheating, consider adding an auxiliary radiator. An additional muffler can help reduce engine noise.

Q: My Grizzly 700 sometimes smokes on startup. Is this serious?
A: Yes, this can indicate valve issues. It's best to have a Yamaha dealer diagnose the problem or check the engine valve clearance for adjustment.

Q: Why is my Yamaha Grizzly 700 difficult to cold-start?
A: For 2016 and newer models, this was often caused by a weakened decompression spring. Yamaha issued a recall for this, so contact your dealer for a replacement part.

Q: What should I check if my Grizzly 700 has poor acceleration?
A: The most common cause is a clogged air filter, which restricts airflow to the engine. Ensure your air filter is clean and properly seated, applying filter grease if necessary.

Conclusion

In summary, while the Yamaha Grizzly 700 is undeniably a tough and reliable quad, it does have a set of common issues that owners might encounter. These range from the frustratingly spongy rear brakes after a pad change to more general problems like engine noise, starting difficulties, and stability concerns. However, it's crucial to understand that these problems, particularly the first eight commonly reported issues, are often resolvable with proper care and attention.

Many experienced Yamaha veterans suggest that a significant number of these issues stem from either rider negligence or insufficient maintenance. Adhering to scheduled maintenance routines and taking proper care of your quad can prevent many of these headaches. Furthermore, it's worth noting that some concerns were specific to older model years and have since been corrected by Yamaha in more recent releases. Others are considered isolated incidents that the manufacturer has permanently addressed through product recalls, demonstrating their commitment to product improvement.

With the wealth of information available online and the supportive community of Yamaha riding enthusiasts, diagnosing and resolving these minor problems has become significantly easier, even for a beginning mechanic or a new owner. Ultimately, these reported issues do not diminish the inherent reliability of the Yamaha Grizzly 700 or the sterling reputation of its manufacturer. Understanding these potential challenges simply empowers you to keep your machine running flawlessly, ensuring that the Grizzly remains a fantastic machine that you will undoubtedly continue to enjoy for years to come. You truly can't go wrong with a Yamaha!

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