Small Engine Spark Plug for Lawn Equipment, (2 Pack) Champion CJ8 (843)

What It Is

The Champion CJ8 (843) spark plug is a standard replacement part for small engines in lawn mowers, tractors, and other outdoor power equipment. This 2-pack offers a simple, reliable ignition source for routine maintenance.

Fitment & Compatibility

• Check your engine manual or old plug for the correct heat range and thread size (14mm x 19mm reach, 5/8" hex).
• Common applications: Briggs & Stratton, Tecumseh, Kohler, and Honda engines on walk-behind mowers, riding mowers, and generators.
• Not for all: Avoid on engines requiring a resistor or surface-gap plug (e.g., some Toro or newer Kawasaki models).
• Gap it: The CJ8 comes pre-gapped at 0.030", but always verify with a gap tool—adjust to 0.025"-0.035" depending on engine spec.
• OEM vs aftermarket: This is a quality aftermarket alternative to OEM plugs (e.g., B&S 5092D). Cross-references include J19LM, RJ19LM, and 841.

Key Things to Know

• Installation: Easy—remove the old plug with a 5/8" socket, hand-tighten the new one, then tighten 1/2 turn more (don’t overtighten).
• Common gotcha: If the old plug is seized, use penetrating oil and a breaker bar; a stripped head is a headache.
• Quality: Champion is a trusted brand; these are copper-core plugs that wear faster than iridium but cost much less.
• 2-pack value: Saves you a trip for a second plug if you maintain two machines or want a spare.

Should You Buy It

If you need a straightforward, budget-friendly spark plug for a lawn mower or small engine that uses a standard 14mm thread, this 2-pack is a solid choice. It’s ideal for DIYers doing annual tune-ups on older Briggs & Stratton or Tecumseh engines, but skip it if your equipment requires a resistor, surface-gap, or high-performance plug.