I have a 96 harley sportster xlh 883 and when I start it up it runs funny. It doesn't run at the high RPMs like it used to. It runs slow then fast, then slow and fast, like a sputter. Almost like its not gettin the right amount of fuel. And while it is runnin it blows out black smoke. I took the carb apart and cleaned it and the one jet that unscrews by the float. Someone told me it might be another jet inside the carb but I'm not sure where it is. Is this a carb problem. If so can some one send pics of what it looks like and how to fix it. I'm not familular with with motorcycles. After I cleaned the carb with carb cleaner it seemed to run just a little better but still actin up. If anyone can help I would greatly appreciate it. Thanks

 

Sounds to me like it is running too rich. The sputtering is caused by un-burnt fuel putting the combustion out. The black smoke is also a sign of running rich. Sorry but I'm not a carb guy either, so I can't help you as far as pics, but you might have the wrong jets.

 

Now the damn thing wont even start. does anyone know how the plastic peice in the peacock goes back in? lol i took it of to see if it was gettin the fuel to make sure it wasnt clogged and i think i put it back on wrong. First bike and so far aint doin to well with workin on it. when i put it back on i out both the holes on the top aligned with the two hole on the top of the peacock. is this correct?

 

Black smoke also indicates poor ignition problems. Check your spark plugs, the wires going to the ignition coil, make sure the electrical contacts are clean. There is a ground wire connection where the starter attaches to the engine, make sure it is tight. Make sure the battery is fully charged and the charging system is working.

 

When you first took the carb apart to clean it did you take the rubber Diaphram out of the top the carb migh have been dirty but if you messed with that diaphram getting it set right without damaging it is not the easiest thing ti do and your bike is at the age where that diaphram could be shot and it will cause all kinds of problems...

 

it is a carb problem.. you have to get all the ports and jets clean, i think there is 3 jets in the carb, but atleast 2.. if it wont run off choke the idle port is clogged, that would cause it to idle bad,irratic, running with the choke on will make it run rich and foul the spark plugs and blow a lot of smoke.... most petcocks really arnt suposed to be taken apart, sometimes you can get a rebuild kit for it but it never works rite again, just get a new valve..

 

it's possible that the diaphram in the petcock is leaking, pull off the vacuum line and see if gas has been in the vacuum line, if there is gas there, replace the petcock, they are about $35 at the dealer.

 

Black Smoke = unburnt fuel or too much fuel. If it was a vacuum leak (lean) there would no smoke. Replace your spark plugs and try again. I had a similar problem, turned out to be a bad ground.

 

Plugs and lean it out a bit. Same problem last week. New plugs and adjusting the AF fixed it for me.

 

If the diaphram in the petcock is leaking, vacuum will be sucking gas from the petcock into the intake therefore making a rich running condition. Checking the vacuum line for gasoline will tell you if that is your source of the extra fuel.