Found that Rotax Pic! Both Selbach's And my Kat Sprint bikes -Thing 1 and 2 (factory tuned Yoshi!), couple of fun timers...and the only two I have now, Both 1952, Thumpy, a 500 Comet and Bam-Bam (a 833cc single, runs on Alcohol and Nos -ex Joh Renwick, Makes 100bhp!!).
I'm gonna get thrown off...