For KTM 150-500 XC-W XCF-W EXC EXC-F XWF 2024-2025. - The start/stop conversion kit is designed to provide an alternative to the new combo switch on new bikes. Combination switches don't have the user-friendly feel, and many cross country riders that compete in events with a dead engine start have complained about not being able to start their bike fast enough to get the hole shot.