I kept fiddling with things, and in the process cleverly backed the idle adjustment all the way out. When I started it up after the trip, it idled at redline. Experienced mechanic and biker that I was, I decided something had been jarred in route, and just needed to be "shaken loose", so I took off the next day along the twisty roads of NW Atlanta (Paces Ferry area).
I came upon a 15MPH corner at 35, let off the gas, and ... kept going. It finally hit me the engine wasn't going to slow down, so I grabbed both brakes. I went into the dirt, slowed to 5 or 10, digging all the while into the soft, muddy yard, and hit a huge oak's root with the front wheel locked, and buried nearly to the axle. I did a perfect flip, with a death grip on the bike. I landed upside down, still astride the poor 80, engine racing out of control until the gas drained back out of the carb.
Providence having gotten me this far, I wasn't about to drop the bike on its side, so I laid there collecting gasoline for a couple of seconds until the guy who'd been driving behind me (who nearly ran me over, staring so hard he nearly forgot to stop!) ran up screaming, "What can I do? What can I do?"
Calmly, I gave the obvious answer. "Get this thing off me!"
Total damage: 1 scraped helmet, 1 bloody back (I slid on it an inch or so, still being ridden by the bike), 1 broken headlight, 1 broken mirror, 1 broken headlight ring. $35.97 (this was a loooong time ago!) "Oh, by the way, we adjusted your idle screw. Somebody had backed it all the way out." "What would that do?" "Make it run at redline." Oh. Well.
Moral: Greenhorns who won't admit it usually get what they deserve.
Copyright 1995 Miles O'Neal, Austin, TX. All rights reserved. Miles O'Neal <meo@XYZZY.rru.com> [remove the "XYZZY." to make things work!] c/o RNN / 1705 Oak Forest Dr / Round Rock, TX / 78681-1514