One cylinder at times

the problem is in the ignition system.....check what whacker suggested..a loose wire at the coil, or ignition switch...let us know!!

you should also double check the wires on the back on the ignition , have seen the come loose after being put back on , & if they did clean your tank right it had to come off

Linda it's single fire, I responded to your other post with this question but

1) Bike is 10 years old ,won't hurt to get some new HD plug wires, plugs and possibly the coil it's a single fire as its a twin cam

2) How many miles on the bike, the first year TC motors had the new cam chain tensioners that wear out pretty fast, some last some don't it's worth it if you have 20K or more to have the cam cover pulled and the tensioner shoes examined. If worn replace them with new shoes, or, have the dealer upgrade you to the 06 and up tensioner system, it's much better and you won't be having to do this again. Its time at least age wise to have that done, think of it as the annual body checkup that you do to keep healthy.

I'd bet you have a bad wire or plug, coils usually die and they are done, rarely do they work and misfire occasionally, but it's happened.

You can do this work yourself to save labor but buy a Service Manual so you know what to look for.

Caution the cam change/tensioner change requires some special tools and knowledge so unless you are ready to tackle it I'd leave it to the pros.

Cam chain setup, tensioner in Orange, there is also one behind that plate up top.



Note the significant wear, this shows new to gone..



Note the new tensioner system much better