Yes, the Vapor will also work for the K4, but because the K4 is air cooled, you’ll need the version of the Vapor that comes with the spark plug ring to read engine temperature. Hope this helps!
amzn.to/48l9Qn9 - This link should take you to the Trail Tech 752-119 Vapor Digital Speedometer Tachometer Gauge Kit we use in this video. Thanks for watching!