Some new issues

[wopa20]

I just cleaned up my new toy (oil change, spark plug, spark wire, oiled chain). Suddenly the bike is starting to give me idle issues, which may have been there before but I havent ridden it much. It does not seem to want to idle properly (doing this by ear) when tampering with the throttle screw. I threw some carb cleaner down the intake to see if that improved anything but still not sure. Anyway, I can get it to fast idle but when I back it down it seems to die off. After a little tampering I pulled the plug and it was covered with black soot. A small amount of black smoke is coming out of the rear too. I filled this bike with fresh 92 octane gas (could this have something to do with it? I am leaning toward a carb issue, would use of carb cleaner in the gas/spray be recommended?

[harryredtrike]

sounds like your running rich,reset your carb to factory specs,put a new plug in and run.then see what your plug looks like

[wopa20]

Do you mean to seat the fuel/air screw then turn back 2 full turns?

[harryredtrike]

what machine do you have?

[wopa20]

I have a atc200s, I have found the manual and believe that you are talking about the pilot screw adjustment. Other than the idle screw I havent really tinkered with the carb.

[peter250r]

you want to set the engine speed to an rpm that it will remain steady at. then screw in the fuel mixture/pilot screw until the engine stalls. then wind out half a turn. start the engine again and readjust the idle screw to a lower rpm some where around 1000 - 1200 or so, then see how smoothly it idles. adjust pilot screw in again if necessary till engine stalls then wind out about quarter of a turn. start again and check exhaust to see if theres black smoke.

after this put a new spark plug in and take it for a run for a couple of mins and then check the plug to see how much carbon is on there.

one other thing you can do is adjust the throttle needle. lowering the needle (not clip)it will make it leaner raising it will make it richer.