How do I Repair Stalling Condition on 2005 Polaris 500 EFI?

Problems with either of the Polaris Sportsman 500 EFI's spark plugs can cause the ATV to stall.

One of Polaris' best-selling automatic ATVs, the Sportsman make of quad requires regular maintenance and repairs to keep it running as intended. For minor problems including a stalling engine, Yamaha has included troubleshooting advice in the Sportsman 500 manual to help guide owners through the repair process. Here, owners can learn how to assess and repair three minor problems that may cause the Sportsman 500 engine to stall.

Things You'll Need

• Gasoline with an 87 octane or higher
• Standard wrench
• Spark plug wrench
• NGK BKR6E replacement spark plugs
• Spark plug gap gauge
• Spark plug gap tool
• Wire-bristle brush
• 1 cup of water and 1 tablespoon of baking soda solution
• 12.8 volt replacement battery
• Separately-powered 12.8 volt battery charger

Instructions

Fuel

1. Check the fuel levels first if the Sportsman 500 EFI stalls. The fuel gauge can be found on the front instrument panel.

2. Refuel if the gauge flashes "Fuel" or it is close to empty. Use leaded or unleaded gasoline with a minimum octane number of 87.

3. Inspect the condition of the fuel in the tank. If gasoline residue is watery or gummy, the gasoline may be contaminated. In this instance, owners should take the Polaris Sportsman 500 to the shop to have the tank drained and refilled with fresh fuel.

Spark Plugs

1. Check the spark plugs next. The plugs can be accessed by unscrewing and removing the front cab with a standard wrench and locating the Sportsman 500 EFI's two cylinders. The quad has two spark plugs, one located inside each cylinder.

2. Remove each spark plug cap. Rotate each spark plug using a spark plug wrench and pull gently upward to remove.

3. Inspect the electrode tip of each plug. A normal tip is gray, light brown, or tan in color. If this tip is cracked, burnt, or brittle and white, replace the spark plug with an NGK BKR6E spark plug.

4. Measure the spark plug gap, or the distance between the hook at the end of each spark plug, with a spark plug gap gauge This gap must measure exactly 0.035 inches for the Sportsman 500 EFI to run properly.

5. Elongate each spark plug gap as needed by gently pulling the hook-end of the plug wider with a spark plug gap tool.

6. Shorten each spark plug gap if needed simply by pressing the hook-end against a firm, flat surface.

7. Screw each spark plug back into its respective cylinder with the spark plug wrench, return each spark plug cap, and reinstall the front cab.

Battery

1. Check the Sportsman EFI's battery next by unscrewing and removing the seat and rear cab to access the battery case.

2. Remove the battery from its case by undoing the straps holding it down and disconnecting the battery cables. The negative (black) cable should be removed first, followed by the positive (red) cable.

3. Inspect the battery's terminals. For corroded terminals, scrape away corrosion with a wire-bristle brush. For dirty terminals, clean with a solution of one cup of water and one tablespoon of baking soda.

4. Replace the battery with a 12.8 volt battery if the original is damaged.

5. Charge the battery fully to 12.8 volts with a separately-powered battery charger.

6. Reinstall the battery, connecting the positive (red) battery cable first and the negative (black) cable second. Secure the battery with its hold down straps and reinstall the rear cab and Sportsman 500 seat.

7. Restart the engine. Take the Sportsman 500 EFI to the shop if it continues to stall.

Tips & Warnings

• A Polaris-certified dealer is best equipped to diagnose and repair major problems if troubleshooting fails.

• Gasoline is highly flammable, so do not smoke or work near an open flame while handling fuel.

• Battery acid can burn skin and eyes. Wear gloves and goggles to avoid burns.

• Only use the spark plug and fuel recommended for the Polaris Sportsman 500 EFI in its owners manual. Using unspecified parts can cause permanent engine damage.

References

• ATV Source: Sportsman 500 EFI
• Polaris Industries: 2006 Sportsman 500 EFI Owner's Manual