According to the Champion plug web site they are both bantam height. But a different bantam height.
I ran into this and found that the plug looked different where the wire connected and sealed t the plug and that was the only difference.
The main difference between the Champion CJ8Y and CJ7Y spark plugs lies in their heat range and design specifications. The CJ8Y has a higher heat range, making it suitable for engines that operate at higher temperatures or require a longer plug life, while the CJ7Y is designed for standard applications with a lower heat range. This means the CJ8Y can handle more demanding conditions without fouling, whereas the CJ7Y is typically used in engines with less thermal stress. Always consult the engine manufacturer's specifications to determine the appropriate spark plug for your specific application.
cj6y and cj7y are identical
CJ7Y works with no issues.
autolite 2974 or xst2974 (irridium) champion rcj7y, cj7y ngk bpmr7a
Champion CJ7Y Champion RCJ6Y Autolite 2974 Bosch WSR6F Denso W22MP-U NGK BPMR7A
Champion CJ7Y or NKG BPM7A or Megafire SE-Y7C or Bosh WS7F
In place of the JENN FENG 9295-331501, I am successfully using a NGK (7021) BPM6A sparkplug; Which is cross referenced to two Champion plugs CHAMPION CJ8Y or CJ7Y
While both the Champion CJ7Y and DJ7Y spark plugs are designed for small engines, they have different heat ranges and electrode designs. The CJ7Y is a hotter plug with a projected tip, while the DJ7Y is a cooler plug with a non-projected tip. It is not recommended to interchange them as it can affect engine performance and potentially cause damage. It's best to use the spark plug recommended by the manufacturer for optimal engine function.
No, you cannot directly replace a CJ7Y spark plug with a CJ8 spark plug. The CJ7Y and CJ8 are different spark plug models with variations in heat range, thread size, and reach. Using an incompatible spark plug can lead to improper combustion, engine misfires, and potential damage to the engine. It is crucial to use the correct spark plug recommended by the manufacturer for optimal engine performance.