Cleaned Carb now Idle Questions

I bought my atv about 2 months ago and it is a 99 and I decided I would go ahead and clean the carb and install a stock kit. I took everything apart and cleaned it and intalled the new parts just like I was supposed to. I have been trying to get it to idle right by ear and i'm not sure if what i'm hearing is normal for an atv. My book says to turn the pilot screw 2 5/8 out and adjust the idle speed screw but if I leave it at 2 5/8 when I rev the motor up it backfires. Is this normal? Also When it is just at an idle you can hear the motor spit a little bit but it's real queit and I dont know if that is a normal exhaust sound or should it be a nice steady rumble from the exhaust all the time. I'm borrowing a tach meter tomorrow so I can do it just like the book says but what do you guys think? Also if I tap the throttle a few times real quick the motor acts like it's gonna die. Does that sound normal and how can I fix that? I'm thinking If I cant get it to idle just right i'm gonna take it to someone but i'm going riding this weekend so I hope it doesn't leave me stranded. it doesn't shut off when it's idle so I guess it will be okay to ride for now.