My Harley Davidson 2002 Heritage Soft Tail is only fireing on one cylinder I put new plugs in but its still only fireing on one cylinder.I pulled off plug wires one at a time,no change w/front wire but when I put it back on & pulled the back one it cut off.

I'm not sure how old this question is, but I'll try and help anyway! First of all on any motor you need fire/spark and fuel to run! The first thing I'd do is verify you have spark to the front cylinder, that sounds like the problem area! The best way to do that is buy one of those spark tools you can get at Harbour Freight or just about anywhere on line! You just plug it in-line with the plug in question and you should see it light up, if not, then your wire is not connected properly, plug is bad or worst case the coil has issues! You can take the coil off and take it to most ORiley's or Advances and they'll check it for you or of course the HD shop! My guess is your getting gas, otherwise the rear cylinder wouldn't be firing! Just to be safe you can always check the fuel injectors to make sure their squirting out the gas like their suppose to! I would highly reccommend getting a Maintenance manual also! If you out on the road your going to need to stock up on a few spare parts, like,spark plug,spark plug wire, an injector would be handy to have, and even a coil if your traveling a long ways without a breakdown vehicle! Also, a spare belt for the belt drive folks and anything you might think could break that you can afford to buy and have room to carry! If you try and be prepared for anything and everything that might go wrong, you'll have years of great biking, wont get stranded and might even be able to help a fellow Biker along the way!! Good Luck!!! COPASETIC!!!!

Its the front one thats bad--chec the wire-it rots from the inside or it may be disconnected from the coil--plug could be fouled or bad or no gas is gitten to that cylinder---------troublshootn test are a must and so is a clymer manual

I'm sorry but I can't help you with your 2002 Harley. They have all the electronics on them that I know nothing about. I work on the older model bikes, Evolution and earlier, not fuel injected. The only thing I can tell you is to check the compression on the front cylinder and the ignition spark to determine if either of those things are missing. Sorry I can't be of more help.

Good Luck
Steve