I have a 92 xl1200 with 24000 miles. Replaced the plugs and noticed the rear plug looks great,but the front plug was black and carboned up if that is a word I guess rich looking. Shouldn't both plugs look the same? Help please.

 

Technically, I would say yes. They should both be the same, or real close. Someone may have another opinion, but I would say it could possibly bethat you have a weak cylinder, or possibly something simple as a bad plug wire, on that one? Maybe even just a bad plug.
It really could be a few things, and possibly something simple.
Try a compression test, to see how the cylinders compare.That may eliminate the possibility of a more major problem.
Good luck, and let us know what you find out.

 

You may have a spark plug that is not firing as hot as the other. Or, it may be that the plug electrode is not in the same position as the other in relation to the intake valve and its fuel burst. Thus, not fully combusting in the cylinder. Sometimes, just a fraction difference will result in the firing being slightly different. If its running ok, no missing, decent gas mileage,you should be ok. I'd change the plugs first to see if it made a difference. Gap them correctly. That could also be your problem.

 

Thanks for the information. The bike runs great. Just thought both plugs should be simular. I put new plugs in and I will run it for awile and check them again.
Thanks PMZ