Honda HS720 Problems? Master Your Snow Blower With This Guide

The Honda HS720 is a powerhouse single-stage snow blower, revered for its reliability and robust performance. However, like any piece of machinery, it can encounter issues that leave you stranded in a winter wonderland. Understanding the most common Honda HS720 problems is the first step toward a quick fix and a clear driveway.

This comprehensive guide will walk you through troubleshooting and resolving the most frequent issues, from frustrating engine start-up failures to lackluster snow-throwing performance. We will provide actionable solutions to get your machine running smoothly again. By following these steps, you can tackle winter’s worst with confidence.

Problem 1: The Engine Refuses to Start

One of the most common complaints is an engine that won’t start, whether using the pull-cord or the electric starter. This is often frustrating, especially when you have a mountain of snow to clear. The causes are typically simple and can be resolved with basic troubleshooting.

Fuel System Issues: The Usual Suspect

The vast majority of starting problems trace back to the fuel system. Old or stale fuel is a primary culprit, as gasoline can degrade in as little as 30 days, especially fuel containing ethanol. Degraded fuel can clog the carburetor’s tiny jets and passages, preventing the engine from getting the proper air-fuel mixture it needs to ignite.

First, check the fuel level and ensure the fuel valve is in the “ON” position. If the fuel has been sitting since last season, it’s essential to drain it completely from both the tank and the carburetor bowl. You can access the carburetor drain screw through a small hole on the left rear side of the snow blower, allowing you to empty the old fuel without major disassembly.

After draining, refill the tank with fresh, high-quality gasoline (87 octane or higher) treated with a fuel stabilizer. This preventative step is crucial for off-season storage, as it keeps the fuel fresh for up to 24 months and prevents the carburetor from gumming up. Before attempting to start, let the fresh fuel run for a few seconds to fill the carburetor bowl.

Spark Plug and Ignition Failures

If the fuel system checks out, the next step is to inspect the ignition system. The spark plug is a critical component that can become fouled with carbon deposits or worn out over time. A weak or nonexistent spark will prevent the engine from starting.

To check the spark plug, first, allow the engine to cool completely. Disconnect the spark plug cap and use a spark plug socket to carefully remove the plug. Inspect the electrode for signs of fouling (a black, sooty appearance), oil, or damage. The gap between the electrodes should be between 0.7 and 0.8 mm; you can measure this with a feeler gauge.

If the plug is dirty, you can clean it with a wire brush and brake cleaner, but replacement is often the best and most affordable option. When installing a new or cleaned plug, thread it in by hand to avoid cross-threading, then tighten it with the wrench. Do not overtighten, as this can damage the cylinder head.

Problem 2: Auger Won’t Turn or Throws Snow Weakly

You’ve managed to start the engine, but when you engage the auger, nothing happens, or it throws snow a disappointing few feet. This issue cripples the machine’s primary function and points to problems with the power transmission from the engine to the paddles. This can be especially frustrating when dealing with heavy, wet snow.

Inspecting the Auger Drive Belt

The most common cause of a non-spinning auger is a worn, stretched, or broken drive belt. The belt connects the engine’s pulley to the auger pulley, and if it loses tension or fails, it cannot transfer power effectively. Over time, the rubber belt will naturally degrade and require replacement.

To inspect the belt, you will need to remove the belt cover. Check for visible signs of wear, such as cracks, fraying, or glazing (a shiny appearance). A loose belt may also be the issue; when the auger clutch is engaged, the belt should be taut. If the belt is damaged or stretched, it must be replaced with a genuine Honda OEM part to ensure proper fit and performance.

Worn Paddles and Scraper Bar Impact

If the auger is spinning but the snow-throwing distance is poor, the issue likely lies with the rubber auger paddles and the scraper bar. The paddles are designed to make contact with the ground, pulling the snow into the housing and propelling it out the chute. As they wear down, the clearance between the paddles and the ground increases, drastically reducing their effectiveness.

Likewise, the scraper bar, located at the bottom of the auger housing, is a critical wear item. It directs the last layer of snow into the paddles. A worn scraper bar allows snow to pass underneath the machine instead of being thrown. For optimal performance, always replace the scraper bar and the auger paddles at the same time. This ensures the machine clears down to the pavement and throws snow with maximum force.

Problem 3: Engine Surges, Sputters, or Runs Rough

An engine that surges—revving up and down erratically—or runs rough is a clear sign of an inconsistent fuel supply or airflow. This can happen after the machine has been running for a few minutes or immediately upon start-up. It indicates that the delicate balance of fuel and air required for smooth operation is off.

The Carburetor: Clogged Jets and Passages

Once again, the carburetor is the most likely source of the problem. Even tiny specks of debris or varnish from old fuel can partially block the main jet or pilot jet. A partially clogged jet restricts fuel flow, causing the engine to run lean, which leads to surging as the governor attempts to compensate.

A thorough carburetor cleaning is often required to solve this. This involves removing the carburetor, disassembling it, and cleaning all jets, passages, and the float bowl with carburetor cleaner and compressed air. For those unfamiliar with small engine repair, a simpler first step is to try a high-quality fuel system cleaner additive in a fresh tank of gas, which can sometimes dissolve minor blockages.

Water in the Fuel and Vented Gas Cap

Water contamination in the fuel is another potential cause of rough running. Water is denser than gasoline and will settle in the bottom of the fuel tank and carburetor bowl, getting drawn into the engine and causing it to sputter. Draining the fuel system is the only way to remove the water completely.

A less common but possible issue is a clogged fuel cap vent. The gas cap has a small vent to allow air to enter the tank as fuel is consumed, preventing a vacuum. If this vent becomes blocked by dirt or ice, it can starve the engine of fuel, leading to stalling or rough performance. Ensure the cap is clean and the vent is clear.

Problem 4: Discharge Chute Is Clogged or Fails to Rotate

The ability to direct the discharged snow is crucial, and when the chute clogs or gets stuck, it can bring your snow clearing to a halt. These issues are particularly common in heavy, wet, or slushy snow conditions. Fortunately, the fixes are often straightforward.

Clearing Clogs and Preventing Future Blockages

A clogged chute is usually caused by moving too quickly in deep, wet snow or by stopping forward motion while the auger is still engaged. Always shut off the engine completely before attempting to clear a clog. Use the provided chute clean-out tool, never your hands, to safely remove impacted snow and ice.

To prevent future clogs, apply a non-stick spray, like silicone or a specialized snow-repellent spray, to the inside of the auger housing and the discharge chute. This creates a slippery surface that helps wet snow slide through more easily. Adjusting your ground speed to match the snow conditions is also critical; allow the machine time to process the snow effectively.

Troubleshooting a Stuck Chute Control

If the chute will not rotate, the problem is often mechanical. The rotation is controlled by a lever that moves a set of gears. These gears can become packed with ice or debris, preventing movement. Small pebbles picked up during operation are notorious for jamming the gear mechanism.

Disassembly of the top cover may be required to access and clean the gears. Once cleared, apply a water-resistant lithium grease to the gears and the chute’s rotating ring to ensure smooth operation. In some cases, the control cable itself may bind or break, requiring adjustment or replacement to restore function.

Preventative Maintenance: The Key to a Problem-Free Winter

The best way to deal with Honda HS720 problems is to prevent them from happening in the first place. A consistent maintenance schedule will ensure your snow blower starts on the first pull and performs reliably all winter long. Proper off-season storage is just as important as pre-season preparation.

When winter ends, it’s time to store your equipment correctly. Proper storage in a dry location, like a garage, is essential. This is especially true if you have a master bedroom over the garage, as you’ll want to avoid any fuel fumes. As you transition to warmer weather tasks, like preparing your garden soil for grass seed, taking a few extra minutes to service your snow blower will pay dividends next winter.

Maintenance Task	Frequency	Key Steps and Recommendations
Change Engine Oil	Annually (or every 50 hours). First change after 5 hours for a new machine.	Use Honda 5W-30 oil. Drain the oil while the engine is warm to ensure impurities are removed.
Inspect Spark Plug	Before each season and after every 100 hours.	Check for fouling and proper gap (0.7-0.8 mm). Replace if electrodes are worn or the insulator is cracked.
Fuel System Management	Before storage and at the start of the season.	Use fresh, stabilized fuel. For long-term storage, either drain the fuel system completely or fill the tank with stabilized fuel and run the engine until it stops.
Inspect Auger Paddles & Scraper Bar	Before each season.	Replace paddles if they are worn past the wear indicator hole. Always replace the scraper bar with the paddles for best performance.
Check Auger Drive Belt	Annually.	Inspect for cracks, glazing, and proper tension. Replace if any signs of wear are visible.
Lubricate Chute Mechanism	As needed or annually.	Apply a water-resistant grease to the chute rotation gears and ring to prevent it from sticking.
Check Tire Pressure (if applicable)	Before each season.	Ensure tires are inflated to the manufacturer’s specification for proper handling and traction.

The Unspoken Problem: Scraper Bar Adjustment and Its Hidden Impact

Many users focus on the engine and auger paddles, but few understand the critical role of the scraper bar’s condition and contact with the pavement. The HS720 is an “auger-propelled” machine, meaning the rubber paddles making firm contact with the ground help pull it forward. The scraper bar sets the height of this contact.

A worn scraper bar not only leaves a layer of snow behind but also increases the clearance between the paddles and the surface. This forces the operator to push down on the handlebars to get a clean scrape, which is counterintuitive to how the machine is designed to be used. This extra effort can lead to fatigue and makes the machine feel less powerful.

Proper scraper maintenance is the key to effortless operation. When replacing the scraper bar, ensure it is installed correctly so the auger paddles make firm, consistent contact. This simple component is the foundation of the machine’s clearing and self-propelling capability, and keeping it in good condition transforms the user experience from a chore into a seamless task. Proper machine storage, perhaps in a garage where you might also be investigating a buzzing noise in the ceiling, will also protect components like the scraper from premature rust and damage.