It's a phase that can last a lifetime!
Thumpers in my life, 250 Matchless, GoldStar, BSA 441, BSA B50MX, Indian Velocette 500, Yamaha SR500, Yamaha TT500, Yamaha Exciter 250, Honda XR100, Honda XR250R, Honda GB500,(Still here), Royal Enfield G5.
When I was racing motocross in the 60s and 70s in Oklahoma, my nickname was Valves, as I also had a couple of Triumph powered racers, too, a Cheney Triumph and Grumph(Greeves Triumph). My friends there still call me that.
Bare