RC12YC BKR5E Spark Plugs for MTD 759-3336 Champion Briggs 491055S 692051 792015 kohler 12 132 02-S John Deere M78543 M8754 Autolite 3924 Spark Plug (4 Pack)

What It Is

This 4-pack of RC12YC/BKR5E spark plugs fits most walk-behind mowers, riding tractors, and small engines from Briggs & Stratton, Kohler, John Deere, MTD, and others. They ignite the fuel-air mix to start and run the engine.

Fitment & Compatibility

Before buying, verify your engine’s spark plug gap (factory spec is 0.030” for most) and thread size (14mm x 19mm reach). Check your owner’s manual or old plug for cross-reference numbers: Champion RC12YC (or RC12YC equivalent), Autolite 3924, NGK BKR5E, Briggs 491055S, 692051, 792015, Kohler 12 132 02-S, John Deere M78543/M8754, and MTD 759-3336. These are aftermarket replacements—not OEM—but meet or exceed OEM specs. Measure the old plug’s hex size (5/8” or 13/16”) to ensure your socket fits. Not for engines requiring resistor plugs (R prefix) unless explicitly listed.

Key Things to Know

• Gap must be checked: Even “pre-gapped” plugs can be off. Use a gap tool and set to 0.030” (or your engine’s spec). Too wide causes misfires; too narrow reduces power.
• Easy install: Unscrew old plug with a spark plug socket, hand-thread new one to avoid cross-threading, then torque to 20–25 ft-lbs (or snug plus 1/4 turn). No special tools needed.
• Quality note: These are budget-priced but have strong reviews (4.8/5). Expect decent lifespan (around 100 hours) under normal use. Not for high-performance or commercial mowers running extended hours.
• Common gotcha: If your engine uses a resistor plug (e.g., BPR5ES), these non-resistor plugs may cause radio interference or rough idle. Check your old plug’s markings.

Should You Buy It

If you have a standard residential mower or tractor with one of the listed engines, this 4-pack is a solid value—cheap per plug, reliable enough for seasonal use, and easy to install. Skip it if you need resistor plugs, have a commercial engine, or want OEM-branded parts for warranty reasons.