Dirt Bike Spark Plugs: What to Know About Them

dirt bike spark plugs

Dirt Bike Spark Plugs – Understanding a dirt bike involves many things outside of knowing proper maintenance and cleaning. When owning a dirt bike, it is important to understand its different parts to properly care for it and ensure it is in top shape. Among the different parts to understand is dirt bike spark plugs. Spark plugs are vital for petrol engines, creating strong sparks to start the engine easily, perform well, emit fewer emissions, and use fuel efficiently.

They send sparks to the engine frequently, from 500 to around 5,000 times per minute, enduring heat and pressure changes. This wears them out, so manufacturers recommend changing them regularly. Spark plugs are like the engine’s ignition switch, sparking once per revolution in a two-stroke engine and every other revolution in a four-stroke one. This guide keeps things simple while explaining how spark plugs work.

Factors of Dirt Bike Spark Plugs

When understanding and choosing spark plugs, there are two main parts of the plug to keep in mind and they are:

Spark Plug Gap

The spark plug gap is the distance between the center and side electrodes. A too-large gap can cause the plug to misfire, while a too-small gap leads to premature ignition, disrupting the compression stroke timing. Incorrect gap size can also result in higher engine temperatures. A properly set spark plug gap ensures precise firing timing and optimal fuel combustion.

To establish the right gap, you’ll need a spark plug gap tool and your bike’s owner’s manual. The manual specifies the suitable gap (like 0.5mm, 0.6mm, 0.7mm, etc.) for your bike’s Make, Model, and Year (MMY), while the gap tool measures the current gap. The gap may change due to rough handling during shipping or storage. The gap tool lets you adjust the gap as needed, ensuring proper performance.

Spark Plug Number

If you plan to buy a spark plug, you should know not all plugs are the same. To choose wisely, first, ensure compatibility with your bike’s Make, Model, and Year (MMY) by checking the owner’s manual. Also, pay attention to the numeric code like “B8ES” or “BKR7EIX” on the spark plug. This number guides your choice, with higher numbers indicating cooler plugs.

Use a lower number in spring and switch to a higher one in summer to avoid engine damage. Your bike’s manual suggests the best spark plug number based on the season and location. Additional numbers and letters in the model reveal details like length and electrode type, impacting spark quality and fuel efficiency.

Changing Spark Plugs

Just as it is important to know how to clean an air filter and check the tire pressure, it is important to know when and how to change your spark plugs. As stated, spark plugs vary, and depending on the bike, there are different ways to change a plug:

4-Stroke Dirt Bikes: Refer to your owner’s manual for the recommended service interval for changing spark plugs in 4-stroke dirt bikes. If you prefer a simpler approach or don’t have the manual, consider changing the plug around once a year, especially if you ride mostly on weekends. Another good time for replacement is during an engine rebuild.

2-Stroke Dirt Bikes: The oil mixed with gasoline in 2-strokes can lead to faster spark plug fouling, depending on carburetor tuning. While checking the owner’s manual is helpful, many 2-stroke riders tend to richen their carburetor settings, which accelerates fouling. If you ride a 2-stroke dirt bike, it’s a smart move to carry a spare spark plug in your toolbox. The spark plug’s easy accessibility on the cylinder head makes regular pre-ride checks convenient and necessary.

The Process

Step 1: Start by removing the spark plug. First, take off the spark plug cap and then loosen the spark plug using a socket wrench or a spark plug wrench.

Step 2: With the old spark plug out, insert the new one in its place.

Step 3: Tighten the new spark plug, but be cautious not to overtighten it. Excessive tightening can damage the thread in the cylinder head, leading to expensive repairs. Also, be careful to avoid snapping the spark plug by overtightening.

Step 4: Once the spark plug is securely tightened, put the spark plug cap back in place.

If you want to explore other dirt bike parts, check out the best dirt bike skid plates and air filters. You can also check out ways to maintain your bike such as dealing with flooding.

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