404 Spark Plug

The Champion 404 Spark Plug is a copper plus resistor spark plug engineered for reliable ignition in small engines and light-duty equipment. With a 14mm thread diameter and 0.750-inch reach, this plug delivers the precise fit and performance characteristics required for consistent cold starts and smooth operation across varying load conditions.

The gasket seat design provides a secure, leak-free seal in the cylinder head, while the resistor core suppresses electromagnetic interference that can degrade engine performance or electronic components. Champion's copper core technology promotes faster heat dissipation than standard nickel plugs, extending the thermal window and reducing fouling in engines that operate at variable RPMs or under demanding conditions. The 0.750-inch reach ensures proper electrode positioning in the combustion chamber, critical for consistent flame kernel formation and fuel ignition timing.

This spark plug is suitable for lawn and garden equipment, portable generators, small pumps, and other light-industrial or residential applications where OEM reliability and correct thermal range are non-negotiable. Users operating equipment in dusty environments or at high altitude appreciate the resistor's role in maintaining electrical system stability. The compact design (1 x 0.85 x 3.8 inches) fits standard spark plug sockets without modification, making replacement straightforward for equipment operators and field technicians alike.