What are the standards for motorcycle spark plug replacement?

The standard for motorcycle spark plug replacement depends primarily on the condition of the spark plug, mileage, and vehicle performance. Specific criteria and precautions are listed below:

1. Replacement by Mileage

Ordinary nickel alloy spark plugs: Recommended replacement every 10,000-20,000 kilometers.
Platinum/iridium spark plugs: Longer lifespan, can be replaced every 30,000-50,000 kilometers (refer to manufacturer's recommendations).
Iridium-platinum spark plugs: Even longer lifespans, can be replaced every 60,000-80,000 kilometers.
Note: Long-term short-distance driving, frequent starting and stopping, or high-speed, high-load riding require a shorter replacement interval.

2. Visual Inspection

After removing the spark plug, observe the following abnormalities and replace it:
Electrode wear: The center electrode becomes rounded or the side electrodes become thinner (excessive gap).
Severe carbon deposits: The electrodes or ceramic insulators are covered with black oil or carbon (maybe an overly rich mixture or oil burning).
Oil stains or wet stains: Oil stains on the spark plug (maybe engine oil blowby). Cracks/breakage in the ceramic body: May cause leakage or misfire.
Erosion or Meltdown: Whitening of the electrode or the presence of melt pits (premature ignition, overheating, or mismatched fuel grades).
Abnormal Color: Normal color is light brown; grayish-white (overheating), black (carbon deposits), or red (fuel additive deposits) are all abnormal.

3. Symptoms of Performance Degradation

Spark plugs may need inspection or replacement if the following symptoms occur:
Difficult Starting: Delayed starting on a cold or hot engine.
Unstable Idle: Noticeable engine vibration and rpm fluctuations.
Weak Acceleration: Sluggish throttle response and decreased power.
Increased Fuel Consumption: Reduced Combustion Efficiency.
Exhaust Pipe Blowback: Unburned air mixture burns in the exhaust pipe.

4. Spark Plug Gap Check

Use a feeler gauge to measure the electrode gap. If it exceeds the manufacturer's specified range (usually 0.6-1.0mm), adjust or replace.
Note: Manual gap adjustment is not recommended for platinum/iridium spark plugs to avoid damaging the electrode coating.

5. Other Notes

Matching Model: When replacing, select the same calorific value, thread size, and electrode material as the original.
Torque Specifications: Tighten according to the manual (usually 10-20 N·m). Too loose may cause air leakage, while overtightening may damage the cylinder head threads.
Regular Maintenance: Spark plugs may be disassembled and cleaned every 5,000 kilometers (optional, depending on the situation).