Do not do that, as you aren't adjusting idle but simply increasing throttle.
First, wiggle the carb about and tighten up all of the hose clamps on the rubber mounting bits. I don't care if they're already tight. Unscrew them a little bit, re-snug the carb into the engine, and tighten them again. We don't want any errors with this. Then, warm the bike up. I don't care how you do it, just do it. Maybe take it out for a short jaunt. If it's winter, you want the condensation from the exhaust pipe to be almost completely evaporated. Then, put a brand new spark plug in. They're only like $1.25, and you want to start completely fresh. You can not skip this step, as an improperly tuned carb will only mess with the plug, which will cause to to tune it improperly again. NO EXCEPTIONS.
Put the bike on the centerstand, and adjust the big thumbscrew down as far as it will go without killing the bike. If you have a tach installed, you're looking for 600-800 RPM max. I know the AVL is supposed to idle at 1,000 +/- 100 RPM, but this is a special case. Then take a flathead screwdriver and screw the small screw (a fuel screw on the Mikuni CV carb, but most here will call it an air adjuster/air screw, because that's how all of the other carbs on Enfields work) all the way in, clockwise.
The bike will die. That's okay. If you are paying attention, you may be able to grab the decomp just-in-time to keep it from potentially fragging your sprag, though I've killed my bike plenty of times without the decomp and I've been fine. Unscrew that small screw you just did out 1 and 1/4 full turns total. Kickstart the bike up and see if it will idle. If it idles nicely with the warm engine, you're done. If not, unscrew it in 1/4 increments (adding more fuel into the idle/pilot circuit) until the idle is where you want. Then and only then do you fine-tune with the big screw. If you have to unscrew it more than 2.5 turns, I would BARELY adjust the thumbscrew up a bit, and start over. You're aiming for 800-1100 RPM at idle, though the stickers on the bike and the manual want 1,000 RPM for the AVL it's pretty safe down to 800. 600 is too little, and you run the risk of killing the bike at stops, and the alternator works for shit below 700 RPM, but 900 seems to put the ammeter just into the +charge side with a 50W headlight on.
The big screw only sets the stop for the throttle. If you adjust that too high you will easily take the carb out of the pilot circuit and into the needle circuit, which bypasses the idle circuit, making it useless and making the bike jump it's idle around way too much depending on engine temp and air temp. This is a Bad Thing (tm). Properly tweaking with the pilot fuel screw will ensure a nicely idling bike with no chance of messing it up when you have to do an 'on the fly' adjustment with the big thumbscrew.
By adjusting it too high with the thumbscrew you will also run the risk of fouling the sparkplug at "idle," potentially causing the bike to die, or leaning it out at "idle," causing overheating problems, in traffic or at lights. These, too, are Bad Things (tm). You don't want to have to rely on electric start or a kickstart at a stop light, and people will laugh at you if you have to pull over. Being laughed at is also a Bad Thing (tm), and avoiding it is the best course of action.
Topic: adjusting idle (Read 7816 times)