The KTM 640 Adventure uses H1 bulb size for both high beam and low beam headlight applications. The replacement chart covers vehicle production spanning 1998 to 2008.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The H1 bulb is the sole bulb type specified for the KTM 640 Adventure across both the high beam and low beam headlight positions for the 1998-2008 model years.
The H1 is a single-filament halogen bulb, meaning one filament handles one lighting function. Because of this, separate H1 bulbs are required for the high beam and low beam circuits rather than a single dual-filament unit serving both.
H1 bulbs operate at 12 volts and 55 watts, which are standard ratings for halogen headlight applications in this class of vehicle.
The H1 uses a P14.5s base, a single-pin connector type. This base design is not interchangeable with other common halogen bases such as H4 or H7, and substituting a bulb with a different base is not possible without modifying the socket.
The H1 is an ECE-rated standard, meaning it conforms to the Economic Commission for Europe lighting regulations used across Europe and many other markets worldwide. It also carries approval for use in the United States and Japan.
Because both the high beam and low beam positions on the KTM 640 Adventure use the same H1 specification across all listed years, a single bulb type serves as a direct replacement for either position.