So I bought a 2004 drz110. Test drive it rode mint had a decent first gear low end bog when I really got on it but it sat for a few years so I assumed a little general maintenance(clean carb oil change new spark plug clean air filter) would fix it. First thing I did though is install the fmf pipe that I bought it with the guy never installed it. Other than that bike is 100% stock. So I cleaned the carb and did an oil and filter change used Kawasaki 10w40 oil and k&n KN-112 oil filter. So I fired it up and it is 1 kick fire up almost every time not a big problem. But I noticed at half throttle it sputters in neutral and first didn't really notice it in second. Also seemed to be smoking a little. I got rid of the low end bog it seems after cleaning the carb but this new problem came up. I adjusted the air screw and reset it to closed and opened 1 1/4 turns like the manual says because whoever messed with it before me had it at 2 1/2 turns out. I thought that would fix it but it still has the same sputter. If I open the throttle up then just flat out let it go it'll stall. I haven't replaced the spark plug yet was going to do it tonight. But after reading around the forum I'm having trouble finding an answer that'll help with my specific problem. Most things say it's jetting because of a the new exhaust but I know plenty of people who run stock klx or ttr with an fmf or aftermarket pipe with no problems. From what I'm reading it sounds like maybe it could be a main main problem like it's clogged or not the right one because it means it's running too rich. I didn't remove the main jet when I cleaned the carb so I could believe that it might still be dirty. My plan is the check the spark plug and put a new one in and if I'm still having the sputter to pile the jets and the carb and hit them with some carb cleaner and see if that works. Just wanted some opinions of if I'm going about it right or if I'm totally wrong and there's something else I'm not thinking of wrong with the bike.