Grizzly 700 Common Issues & Fixes

The Yamaha Grizzly 700 stands as a titan in the ATV world, revered for its potent 700cc engine and robust construction, built to conquer challenging landscapes. However, even this formidable machine can encounter its share of hiccups. Understanding these prevalent issues is your first step towards proactive maintenance, potentially saving you from costly repairs down the line. This guide delves into some of the most frequently reported problems faced by Grizzly 700 owners, covering everything from steering quirks to engine performance.

The Yamaha Grizzly 700 is a popular choice for off-road enthusiasts, renowned for its powerful 700cc engine and robust build. Designed to tackle demanding terrain and heavy loads, it's a capable machine. However, like any complex piece of machinery, the Grizzly 700 isn't immune to problems. This article aims to shed light on some of the most common issues reported by owners, including concerns related to steering, braking, engine noise, and other performance aspects. By familiarising yourself with these potential faults, you can better identify and address them, preventing minor issues from escalating into major, expensive repairs.

Common Yamaha Grizzly 700 Problems and Solutions

1. Stability Concerns

One of the most frequently cited issues with the Grizzly 700 revolves around its stability, particularly on uneven terrain or when navigating inclines. Its relatively compact size and lightweight frame, while beneficial in some scenarios, can contribute to a feeling of instability. The ATV's narrower track width and a higher centre of gravity can make it susceptible to tipping sideways or rolling when cornering sharply on slopes. Riders often report a sensation of the quad sliding out from beneath them when riding on off-camber sections. Fortunately, several adjustments can significantly improve stability:

• Body Positioning: Lower your centre of gravity by bending your knees and sitting deeper in the seat, especially when tackling hills or uneven ground. This shifts more weight over the wheels, enhancing stability.
• Speed Control: Entering corners and turns at reduced speeds is crucial. Excessive speed is a primary contributor to rollovers. Maintain controlled throttle and brake application throughout the turn.
• Rider Lean: Lean your upper body into the turn, keeping your weight over the inside wheels. Gripping the fuel tank with your knees helps counterbalance the forces that can cause tipping.
• Differential Lock: Utilise the differential lock button when traction is limited. Locking the rear wheels helps prevent sideways sliding on slippery surfaces.
• Aftermarket Wheel Spacers: For those who frequently ride on challenging terrain, installing aftermarket wheel spacers can widen the ATV's stance, thereby enhancing stability.
• Tyre Pressure: Ensure your tyre pressure is correctly set. Insufficient pressure can allow the tyre sidewalls to flex and slide more easily, compromising grip and stability.
• Rock Sliders/Skid Plates: Attaching rock sliders or skid plates can subtly lower the centre of gravity, further contributing to a more planted feel.

2. Engine Noise and Overheating

The Grizzly 700's single-cylinder 686cc engine is inherently a bit louder and tends to run hotter than multi-cylinder engines. This can translate to a noticeable exhaust note and engine heat, potentially making rides less comfortable, especially during hot weather or when the ATV is idling. Here are some ways to mitigate these issues:

• Exhaust Modifications: Installing a quieter aftermarket muffler or an exhaust silencer designed specifically for the Grizzly 700 can significantly reduce the decibel levels.
• Sound Dampening: Applying sound-dampening materials, such as exhaust wrap, to the exhaust headers and muffler can help tame the noise emanating from the engine.
• Valve Adjustment: If the engine noise is due to excessive valve lash (loose valves), adjusting them to the factory specifications can quieten things down.
• Radiator Maintenance: Frequent cleaning of the radiator is essential to remove accumulated dust and debris that can impede airflow. Use compressed air or a gentle stream of water to clear the cooling fins.
• Coolant Levels: Regularly check that the coolant level is maintained at the recommended mark. Top up with the correct coolant mixture if it appears low.
• Aftermarket Fan Kits: Installing an aftermarket radiator fan kit can improve airflow, especially at low speeds or when idling, thereby enhancing the cooling capacity.
• Radiator Relocation: For chronic overheating issues, consider a radiator relocation kit to position the radiator in a more effectively ventilated area.
• Thermostat Check: Inspect the thermostat and replace it if the engine consistently operates at temperatures above its normal range.

3. Air Filter Performance

The foam air filter on the Grizzly 700 requires diligent maintenance, particularly when riding in dry, dusty conditions. If not properly cared for, it can allow fine dust and sand particles to bypass into the engine, leading to accelerated wear. To prevent this:

• Filter Sealing: Apply a dedicated foam filter sealing grease, such as Yamaha's own filter oil, around the edges and seams of the filter. This creates a seal between the filter and its housing, blocking particle ingress. Reapply this grease after each cleaning.
• Regular Cleaning: Clean the air filter frequently by gently tapping it to dislodge dust or using low-pressure compressed air. Avoid hitting or forcefully knocking the filter, as this can damage the foam structure.
• Filter Replacement: Replace the air filter according to the intervals specified in your owner's manual. A clogged filter restricts airflow, placing an unnecessary strain on the engine.
• Housing Seal: Ensure the air filter housing is properly sealed and the cover is securely fastened. A quick check for suction release when removing the cover can help confirm a good seal.
• Upgraded Filters: Consider upgrading to an oiled gauze filter or a heavy-duty foam filter, which often provide superior filtration compared to standard paper filters.
• Dusty Riding Technique: When riding in very dusty conditions, reduce your speed to minimise the amount of dust forced through the system. Ease off the throttle before coming to a complete stop.
• Air Inlet Extensions: Air inlet duct extensions can be fitted to raise the filter's intake point, moving it away from kicked-up debris.

4. Starting Difficulties (Cold Weather)

Cold weather starting issues on the Grizzly 700 are often linked to the decompression springs. These small springs, located on the camshaft, are designed to reduce compression pressure, allowing the starter motor to turn the engine over for ignition. When these springs weaken or break, compression increases, demanding more power from the battery and making starting significantly harder.

• Replace Decompression Springs: The most effective solution is to replace the original springs with upgraded, high-quality ones from a reputable supplier. The OEM springs are known to fail prematurely.
• Battery Condition: Always use a fresh, fully charged battery in good condition. Cold temperatures reduce battery output, so maximum starting power is essential.
• Starting Fluid: In extremely cold conditions, a small amount of quick-start fluid (like ether) sprayed into the airbox before attempting to start can aid combustion.
• Oil Viscosity: Ensure the engine oil's weight is appropriate for the ambient temperature. Heavier oils increase cranking resistance in cold weather.
• Spark Plugs: Verify that the spark plugs are in good condition and correctly gapped. Worn or fouled plugs can impede starting.
• Valve Lash Adjustment: If excessive valve lash is suspected of increasing compression, have it adjusted by a qualified technician.
• Starter Motor Care: Avoid cranking the starter motor for more than 5 seconds continuously to prevent overheating. Allow at least 30 seconds between cranking attempts.

5. Brake System Responsiveness

The hydraulic disc brakes on the Grizzly 700 can sometimes exhibit a spongy brake pedal feel, leading to reduced stopping power. This is often due to air trapped within the hydraulic system, particularly noticeable after new brake pads have been installed. To restore firm and responsive braking:

• Brake Bleeding: Thoroughly bleed the rear brake system, preferably using a vacuum bleeder tool. This process effectively removes any trapped air bubbles, ensuring optimal hydraulic pressure.
• Brake Fluid Replacement: Replace the rear brake fluid with fresh, DOT-approved fluid. Older fluid can absorb moisture over time, which can compress under braking, leading to a spongy feel.
• Leak Inspection: Carefully inspect all brake components for any signs of fluid leaks. Leaks can allow air to enter the system, compromising brake performance. Tighten fittings or replace damaged parts as necessary.
• Braided Steel Lines: Consider upgrading to braided stainless steel brake lines. These lines are less prone to expansion under pressure and are more resistant to moisture absorption compared to standard rubber hoses.
• Brake Pad Bedding-In: Properly bed in new brake pads by performing a series of moderate stops. This process prevents glazing and ensures optimal performance. Avoid aggressive riding immediately after installing new pads.
• Pedal Adjustment: If the brake pedal still feels soft even after bleeding, check its height adjustment. A pedal that is set too low relative to the master cylinder can affect its responsiveness.
• Pad Replacement: Replace worn brake pads promptly when they reach their minimum thickness. Allowing pistons to extend too far can introduce air into the system and make bleeding more difficult.

6. Electric Power Steering (EPS) Issues

The electric power steering (EPS) system on the Grizzly 700 can sometimes present problems such as jerky steering, delayed response, or even a complete loss of assistance or steering lockup. These issues are frequently linked to electrical faults:

• Battery Voltage: Begin by checking the condition of your battery. Low voltage can directly impact EPS performance. Recharge or replace the battery if it's found to be weak.
• Wiring Connections: Inspect all wiring connections, particularly at the EPS control unit located under the seat. Clean any corroded or loose connectors, or replace them if necessary.
• EPS Fuse: Check the 20-amp EPS fuse. If it has blown, replace it with an OEM fuse of the correct rating.
• System Reset: Try resetting the EPS system by disconnecting the battery for approximately 30 seconds. This can sometimes clear temporary fault codes that may be causing issues.
• Sensor Integrity: Ensure the speed sensor and torque sensor associated with the EPS are clean and undamaged. Malfunctioning sensors will directly affect the system's operation.
• Diagnostic Codes: If problems persist, have a Yamaha dealer scan for diagnostic trouble codes (DTCs) using the specialised EPS tool. This can pinpoint specific faults within the system.
• Control Unit Replacement: A faulty EPS control unit is a common cause of intermittent power steering issues and may need replacement.
• Steering Binding: Check for any binding in the steering mechanism that might be placing excessive load on the EPS system. Ensure the wheels are properly aligned.

7. Gas Tank Rollover Valve Malfunction

The rollover valve is a safety feature designed to shut off fuel flow from the tank if the ATV overturns, preventing fuel spills and potential fire hazards. However, a faulty valve can sometimes activate prematurely, leading to fuel starvation and engine stalling or hesitation.

• Valve Replacement: If you suspect the rollover valve is causing fuel delivery problems, try replacing it with an OEM Yamaha part. Old valves can degrade and malfunction.
• Bypass Kit: If premature activation is suspected, a rollover valve bypass kit can be installed to disable the valve's function, though this should be considered carefully due to the safety implications.
• Vent Line Check: Ensure the vent line running from the rollover valve is clear and not kinked. Blockages in the vent line can lead to improper valve operation.
• Fuel Level: Avoid overfilling the fuel tank. Excessive fuel levels can sometimes cause pressure build-up that triggers the rollover valve. Always leave some room for fuel expansion.
• Inspection and Cleaning: Inspect the valve seal and the bottom filter screen for any damage or debris. Clean these components and replace any damaged gaskets or seals as needed.
• Proper Installation: Verify that the valve is installed with the correct orientation and at the specified height. Incorrect installation can restrict fuel flow.

8. Subpar Acceleration

A common complaint among Grizzly 700 owners is a lack of responsiveness in acceleration, particularly from a standstill. This is often attributable to issues within the fuel delivery or ignition systems:

• Fuel Injector Cleaning: Clean or replace clogged fuel injectors. Using a quality fuel injector cleaner and compressed air can help clear obstructions.
• Spark Plug Replacement: Replace old spark plugs with new ones, preferably iridium plugs, gapped to the manufacturer's specifications. Worn plugs can cause misfires and affect performance.
• Throttle Position Sensor (TPS): Inspect the TPS for erratic readings or out-of-range values. A faulty TPS can significantly impact the fuel mapping and throttle response.
• Intake Leaks: Check for any air leaks in the intake system, which allow unmetered air into the cylinders. Ensure manifold boots and clamps are tightened correctly.
• Air Filter Maintenance: Clean the air filter box and replace the air filter if it's dirty or clogged. Restricted airflow directly reduces engine power.
• Exhaust System: Consider installing a free-flowing exhaust system, such as a slip-on muffler, to reduce back pressure and potentially improve low-end torque.
• Valve Clearance: Verify and adjust valve clearance if necessary. Incorrect valve lash can impede proper airflow at lower RPMs, affecting acceleration.
• Fuel Octane: Always use fuel with a minimum octane rating of 91 to prevent pre-ignition or knocking issues.
• ECU Reset: If acceleration problems arise suddenly and other checks reveal no issues, an ECU (Engine Control Unit) reset might be beneficial.

Frequently Asked Questions

Q1: What causes the spongy rear brake pedal feel on my Grizzly 700?

A1: The most common cause is air trapped within the brake lines. Thoroughly bleeding the rear brake system using a vacuum bleeder tool is essential to remove all air bubbles and restore a firm pedal feel. Replacing old brake fluid with fresh DOT-approved fluid is also highly recommended.

Q2: Why is the 4x4 not engaging properly on my Grizzly 700?

A2: Start by checking the front differential oil level. If the level is correct, the issue likely lies with electrical components such as the 4x4 actuator or servo motor. Inspect all wiring connections for damage or corrosion and consider having a Yamaha dealer scan for trouble codes.

Q3: How do I improve poor acceleration and throttle response?

A3: Begin with basic maintenance: clean or replace fuel injectors and air filters. Also, check the condition of the spark plugs and the throttle position sensor. In some cases, an ECU reset or an upgrade to the exhaust system can help enhance low-RPM power and overall acceleration.

In Summary

While the Yamaha Grizzly 700 is engineered for rugged performance and reliability, it's not immune to the common ailments that can affect any complex machine. Issues such as stability on challenging terrain, engine heat and noise, a less-than-responsive brake pedal, and sluggish acceleration can be frustrating for owners. However, with consistent, diligent maintenance and a proactive approach to troubleshooting, the majority of these common Grizzly 700 problems can be effectively resolved or even prevented altogether. By implementing the solutions and maintenance tips outlined in this guide, you can ensure your Grizzly 700 continues to perform optimally, providing countless hours of enjoyable off-road adventures. With proper care and attention, your Grizzly 700 is poised to deliver years of dependable performance and exhilarating rides.

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