Motorcycle Repair: Suzuki Copy Idle problems, hyosung comet 250, suzuki sv650

Question
Hi,
I just bought a 2004 Hyosung Comet 250. The reason I chose to ask you this question is because it is practically a copy of the Suzuki SV650 (or at least the body work). My problem is relatively general. Before I bought the bike it had been sitting for quite some time. The previous owner could not get it to start so he sold it. I changed the oil, spark plugs, filters, cleaned the carbs and replaced the fuel lines. The bike runs fine now, but it has a bit of a catch. It has very bad throttle response at low RPMs and the acceleration jumps up at around 5k and then again at 9k. In addition I occasionally hear a pop from the exhaust when quickly accelerating and decelerating. It's not a full blown backfire, but I think the bike is running rich. This is my first bike so I don't know very much about engines. Besides not having cleaned the carbs right, could it be something else? What do I do?

Answer
It sounds like there's either an intake airleak or the carbs are still not feeding enough fuel due to blocked jets or channels. When you cleaned the carbs did you remove the idle mixture screw? You may need to adjust idle mixture to get the low throttle response. The surge in power at 5k and 9k indicate that once the bike is running on the needle jet and main jet, it is getting adequate fuel but the delivery is not smooth. Check the operation of the sliders and make sure they are smooth and are operating freely. I like to blow a little compressed air from a foot away and watch the slider operate.