Hi, Bede, This is a classic problem with (ahem) Mamods and Accucrafts. For all the good engineering and high-volume, low-cost production techniques, you would think that Accucraft would have learned by now that the taper on their throttles is far too blunt for good control. This is especially annoying on the Ruby, which would tend to be a runaway in any case with its small bore cylinders.
Anyhow, my son bought a nicely tricked-out Mamod at Diamondhead several years ago and it exhibited the same problem. Richard Ough of the 16mm Society was there that year and promptly said "that's easy to fix!" He unscrewed the throttle valve, chucked it up in a hand drill someone had, and turned the point to a sharper angle with a file. And by gosh it worked! I have done the same (with somewhat more sophisticated tools) on my Ruby and it worked a treat there, too. I think that would go a long way towards fixing your problem. Give it a go. regards, Vance Bass
