In the mid 70s when I was a schoolkid I had Mills 1.3 which I grafted an Enya 09 throttle onto (the local model shop offered the carb for peanuts and no one told me it was sacrilege) with a sleeve I made in the school machine shop. It didn't do much - any setting other than fully shut had no effect on the power at all, and so it ended up as a 2-speed throttle system with the low speed set by the airbleed screw!
This was done as part of the process of converting my 2-year-old DH9a (Eric Coates plan) to take a single-channel RC set I had been given. It flew very nicely until I fitted a bigger fuel tank ('cos it was RC now, so needed a much longer engine run, obviously) and was enjoying it so much the rubber band on the escapement ran out of turns and it headed off south from Radio Hill at Chobham Common, climbing like a good'n. The model, the mills and the escapement are probably still somewhere between Longcross, Guildford and Woking (but probably no longer airborne)...
AS
