Hi
3) Back out on the idle speed screw until it justt doesn't touch the throttle linkage. Then screw it in back about 11 turns (what this does mean actually?)
This is to keep the engine idling without keeping the leg on accelarator padel,
7) Now turn in the A/F screw until engine dies. If this happens, turn out the A.F screw half turn at a time to bring it back. (try to start the car of coz) (what this does mean?)
when turning Af screw in you are leaning the mixture (means you reduce the amount of fuel to a given air intake), when you keep on turning it in engine will die means there is not enough fuel passes throught idle circuit,so that is why they wanted to back it half after engine die, if not car will not start it back
8)Continue to turn out the A/F screw at half turns every 3 seconds. Engine will pick up speed. Continue to screw out until the point engine runs worse. When that happens screw back in half turn every 3 secs to the point engine runs smoothest.(do this by ear or watch engine vibration) (what this does mean?)
turn the af screw out , then engine will start increaing it's rpm , each and every turn you must give few seconds to engine to adjust itself for new settings, stop it somewhere when you feel engine has sufficient rpm and doesn't shake it self or stumble
(if you have a rpm and vacumm guage you should get maximum vacum and your normal idle speed)
as a tip because you are new do this ,
Keep a full glass of water on the engine bay and watch it should not spill or shake much
then try to gas it at once hard it should not stumble or jerk , asssume this is fairly good
black smoke also caused by KO piston ring (what this does mean?).. check the compression
you got worn piston or rims or leaking valve seats or guide , keep the finger inside the tail pipe and see if it is oily then you have a engine repair to be done
if you have oversize carburator main jets none of these will work better you got o reduce them to a lawer size
thanks
regards
sumith