rough running

[tealsoftail]

I have a 01 heritage the only mods are a 2 into 1 thunder header and a stage 1 air cleaner. It also has about 13,000 miles on it. My problem is I can ride all day at 55 or 60 mph with no problems. I can also run at 70 mph for 20 or 30 miles again no problem. But when I run 70 mph for 45 min. to 1 hour I start to notice a little more vibratin in the handle bars and a slight lack of power. If I let the bike set for about 15 minutes it runs fine again. So do you guys have any idea of what could be wrong? Thanks for you help.

 

[tealsoftail]

the bike was set up when i bought it. It has a stock carb. Also when I keep it below 70 it runs like a top. I also get about 38 to 43 mpg with it.

 

[tealsoftail]

I didnt get a chance to check the jets but the plugs were a nice brownish tan. I changed the coil and put screaming eagle wires and platinum harley plugs in it and its running fine. best I can figure the coil was braking down from running higher revs for a longer period of time. but thanks for your help. I will keep the jet size in mind.