About 5 days ago my 2002 XLH 1200 broke down on the side of the road. I started it back up and it ran to my house. It will start and rev in neutral with no problem. It also does fine moving through the yard. Once I get on the street and get to the top of first gear it will start stumbling. I can work my way up through the gears, but it will usually run best around 2400-2600rpms. Pulling the choke while losing power usually give me power back, but sometimes it only makes it a little better. Ive made probably 12 test runs (1-mile) and its died several times but will start right back up. Really the only thing that Ive messed with since I bought it is the wiring with the tail light, and internal wiring in my bars (two months ago), and I put drag pipes with no baffles. Changed the pipes a month or two ago and rejetted. Hadnt had any problems so far.
It feels like its running out of fuel so thats mostly what Ive been troubleshooting. I've checked the vacuum petcock, cleaned the jets, and checked the vacuum piston. There was some tank liner loose in my tank so i pulled it off and cleaned the inside of it. The accelerator pump squirts a good strong stream. I had a vacuum leak at my intake manifold so i replaced both gaskets. Ive also checked the float bowl level, my battery connections, and the coils. I have no idea what to do next.

 

overhaul the carburetor

 

Fuel line?

 

Is the petcock definitely okay? Seems a lot of folk have trouble with these.

I once had a bike that suffered from fuel starvation. Turned out to be the little mesh filter that sits about the float valve was clogged up!

 

Did you physically remove the petcock and check the filter on it? Also, you may want to check the diaphragm of the vacuum piston for any tears and to make sure it was seated properly under the cap.