My 09 Streetglide did the same thing at about 23k. Started fine cold but when hot it sounded terrible like a bang and clunk and would not always fire. I replaced the starter clutch and resolved the issue. I also have a new SE compensator that I am waiting to install when time permits. My guess is the starter clutch.

 

just took my 09 ultra to the shop (not the Harley dealer) today with the same problem. They told me it is the starter clutch.

 

Yup me too... $50 extended warranty deductible and I am good to go now.