Polaris Tech Tip: How to Inspect Polaris UTV/ATV Spark Plugs and Ignition Coils

Tech Tip: How to Inspect Polaris UTV/ATV Spark Plugs and Ignition Coils

A strong, consistent spark is essential for the performance of your Polaris ProStar engine. Because these engines operate at high RPMs and under heavy loads, the ignition system is under constant stress. Fouled plugs or weak coils can lead to "popping" on deceleration, hard starting, and a noticeable drop in power.

Step 1: Reading Your Spark Plugs

When you remove your spark plugs, the color of the insulator tip tells a story about how your engine is running:

• Tan or Light Gray: This is the "perfect" color. It indicates your fuel mixture and heat range are exactly where they should be.
• Black and Sooty: This indicates a "rich" condition. Your engine is getting too much fuel, or you have a clogged air filter.
• White or Blistered: This indicates a "lean" condition or an overheating engine. This is dangerous and can lead to melted pistons.
• Wet or Oily: This suggests oil is bypassing the piston rings or valve seals, or the plug is not firing at all.

Step 2: Inspecting Ignition Coil Sticks

Most modern Polaris models use "Coil-on-Plug" technology. These units sit directly on top of the spark plug and are susceptible to heat and vibration.

• Check for Cracks: Inspect the plastic housing of the coil for "hairline" cracks. High voltage can "leak" through these cracks to the engine block instead of the spark plug, causing a misfire.
• Check the Seal: The rubber boot at the bottom of the coil must be supple and tear-free. If water enters the spark plug well because of a bad boot, the spark will short out.
• The Resistance Test: Using a multimeter, you can check the primary and secondary resistance of the coil. If the numbers are outside the range in your Polaris service manual, the coil is internally damaged.

Step 3: Gapping and Installation

Even a Genuine Polaris OEM Spark Plug should be checked before installation. Plugs can be dropped during shipping, which closes the gap.

• The Gap: Use a wire-style gap gauge to ensure the electrode is set to the exact thousandth of an inch specified in your manual.
• Anti-Seize: Use a tiny amount of anti-seize on the threads to prevent the plug from "welding" itself into the aluminum cylinder head.
• Torque: Always use a torque wrench. An over-tightened plug can crack the porcelain, while a loose plug can blow out of the head!

Pro Tip: The "Fresh Start" Rule

If you are diagnosing a running issue, always start by installing a fresh set of Genuine Polaris OEM Spark Plugs. They are the least expensive part of the ignition system and often the most likely culprit. Never try to "sandpaper" an old plug; the microscopic scratches left behind will actually encourage carbon buildup!

Restore your engine's "pop" and throttle response. Shop Witchdoctors.com for OEM Polaris spark plugs, ignition coils, and dielectric grease today!

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