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Spark Plug Replacement and Upgrade Guide for the 2006 Argo Bigfoot 6x6

Keep your Bigfoot's V-Twin engine running strong with the correct spark plugs and proper maintenance.

4 minutes to read 2006-2006 Argo Bigfoot 6x6
Difficulty
1/5
Est. Time
0.25 hrs
DIY Doable?
✅ Yes
Shop Labor
$25-$50
⚠️ Drivable, but... — You can drive with a failing spark plug, but the engine will run poorly, have low power, and may be very hard to restart, potentially leaving you stranded.
Key Takeaways
  • The 2006 Bigfoot 6x6 uses two spark plugs in its 18hp Briggs and Stratton V-Twin engine.
  • Standard copper plugs like the Champion RC12YC or Autolite 3924 are excellent, affordable choices.
  • Always check and set the spark plug gap to 0.030 inches before installation.
  • Fouled plugs can be a symptom of other engine issues, such as a carburetor problem.
The spark plugs in your 2006 Argo Bigfoot 6x6 are critical to its engine's performance. Your Bigfoot is powered by an 18hp, 570cc V-Twin engine made by Briggs and Stratton. This engine has two cylinders, and each one needs a spark plug to work. The plug takes a high-voltage electrical charge from the ignition system and creates a powerful spark. This spark ignites the mix of air and fuel inside the cylinder. This small explosion pushes the piston down, which turns the engine and ultimately drives the wheels. For your Argo to start easily and run smoothly, this spark must be strong and happen at the exact right time.

Signs of a Failing Spark Plug

When spark plugs get old or dirty, they can't create a good spark. This can cause several problems with your Argo's engine. Because it's a V-Twin, a single bad plug can make it feel like you've lost half your power.

  • Hard Starting: The engine turns over but struggles to fire up and run.
  • Rough Idle: When the engine is running but the vehicle isn't moving, it might shake or sound uneven.
  • Engine Misfires: You may hear popping or sputtering sounds. The engine might hesitate or stumble when you give it gas.
  • Reduced Power: Your Bigfoot may feel sluggish and weak, especially when climbing hills or carrying a load.
  • Black, Fouled Plugs: If you take a plug out and it's covered in black, soft carbon, it's a clear sign it's not working right. This can be caused by a bad plug or another engine issue, like a problem with the carburetor.

Choosing the Right Aftermarket Spark Plug

For the 2006 Bigfoot 6x6, you don't need to buy expensive, fancy spark plugs. Standard copper plugs from well-known brands provide excellent performance. Both Autolite and Champion are common, reliable choices for the Briggs and Stratton engine in your Argo. The most important thing is getting the correct part number that cross-references to the original plug.

Brand Tiers

Good: Autolite 3924

The Autolite 3924 is a dependable copper resistor spark plug that is a direct cross-reference for the original Champion plug. It provides consistent performance for everyday use and is a great value.

Good: Champion RC12YC

The Champion RC12YC is the standard, original-equipment equivalent plug for this engine. It's a proven design that works perfectly for the demands of the Bigfoot's air-cooled V-Twin engine. You can't go wrong choosing this plug for reliable operation.

Pro Tip: Always Check the Gap

No matter which brand you choose, you must check the spark plug gap before installing it. The correct gap for your Bigfoot's engine is 0.030 inches (0.76 mm). Most plugs are set at the factory, but they can get bumped during shipping. Use a simple spark plug gapping tool to measure and adjust the gap. 🎬 Watch: How to gap a spark plug properly An incorrect gap can cause a weak spark and poor engine performance.

Known Issues, Recalls, or TSBs

There are no specific recalls or Technical Service Bulletins (TSBs) from the National Highway Traffic Safety Administration (NHTSA) related to spark plugs for the 2006 Argo Bigfoot 6x6. However, owners of the Briggs and Stratton 18hp Vanguard engine have reported issues with spark plugs fouling (getting covered in black soot). This is often related to problems with the carburetor running too rich or issues with the choke not opening fully, rather than a defect in the spark plug itself. Some owners have also noted that the engine can backfire when shut down hot, which is generally not caused by the spark plugs.

Cost of New Spark Plugs (2006 Argo Bigfoot 6x6)

Category Estimated Cost
New Aftermarket (Autolite, Champion) $3.59 - $11.70 each
Shop Labor $25 - $50

Note: Your Bigfoot requires two spark plugs. Prices are estimates and may vary based on your location and the supplier.

Frequently Asked Questions

How often should I change the spark plugs on my Argo Bigfoot?

For a small engine like the one in your Argo, it's best to inspect the spark plugs annually or every 100 hours of use. If they are dirty or worn, replace them. Given their low cost, replacing them as part of your yearly tune-up is a good practice.

🎬 Watch: How to change the spark plugs on a Vanguard engine
Can I use a spark plug from a car in my Argo?

No. You must use a spark plug with the correct heat range, thread size, and reach specified for your Briggs and Stratton engine. Using the wrong plug can lead to poor performance and serious engine damage. Stick with the recommended cross-references like Autolite 3924 or Champion RC12YC.

What tools do I need to change the spark plugs?

You will need a ratchet, a spark plug socket (usually 5/8-inch for these plugs), and a spark plug gap gauge/tool. The job is very simple and accessible.

Is it worth upgrading to an iridium or platinum spark plug?

For the Bigfoot's engine, it is generally not necessary. Standard copper plugs from Autolite or Champion provide a strong spark and excellent performance. The main benefit of more expensive iridium or platinum plugs is a longer lifespan, not a noticeable power increase. Since the plugs are easy to change and inexpensive, standard copper plugs are the most cost-effective choice.

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Technical Specifications

OEM Part Numbers: RC12YC

Engine: 18hp 570cc Briggs & Stratton Vanguard V-Twin. Spark Plug Type: Standard Copper Resistor. Spark Plug Gap: 0.030 in (0.76 mm). Hex Size: 5/8 inch. Quantity Required: 2.

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Meet Wrenchy → Updated Jul 21, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Spark Plug for:
  • Argo Bigfoot 6x6: 2006
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