The SP24-NS spark plug is specially designed to work with our 24V military spark plug adapter (24VSPA-1). It features the correct 14mm x 1.25 thread pitch, short reach, and shoulder design needed to properly seat and seal when used with the adapter and military shielded cable ends.
Original military plugs like the Autolite 2245 and 2243 were 18mm and designed for waterproof 24V suppression cables. These are now hard to find and costly. Our SP24-NS plug provides a modern, serviceable replacement when paired with the adapter — allowing you to keep the original ignition cable ends intact.
Important Fitment Note: This plug cannot be used alone with military-style 24V cable ends. It must be paired with the 24VSPA-1 adapter for proper function and sealing.
Why Use the SP24-NS Plug?
Correct thread and shoulder for use with our 24V waterproof spark plug adapter
Allows continued use of your original shielded 24V ignition cables
Modern and affordable replacement for obsolete 18mm military plugs
Ensures reliable starts, proper sealing, and correct heat range
