I had the gearing changed on my FLHTC in Sturgis this year and when I picked up the bike and took it up through the hills for a few mile I found that the belt was loose so I took it back and they tightened it up and I thought all was good. after another days riding the same thing happened and I took it back again. The tecs said they had never had this problem before and they thought the back wheel must be moving so they marked it and sent me on my way.
After I left Sturgis I needed to get the belt readjusted again in Anamossa Iowa and again in Texas.
Last weekend I went for a ride and the belt let go on me and I had to get the bike towed . The total miles for that belt is only 3850 and it still looks like new apart from 12/18 in which the inner belt has frayed and that section is now stretchy like a rubber band.
The belt is a 139 tooth 1 In made by BDL and when I rang the company that did the work in Sturgis I was told there is no warrantie on belts. The local stealer has quoted 5 hours at $95 + $200 in parts.
That's a very expensive 4000 miles I think.

 

Have you called BDL?

 

Is the belt a Goodyear Falcon?

 

BDL is closed until next week and yes its a Falcon Belt but BDL

 

I had a BDL Falcon on my bike, started falling apart at about 200 miles. Separated like yours. I went to the shop I bought it at through Bikers Choice and he contacted BDL and they arranged an exchange for a Gates belt. I had installed the belt myself. See if the shop that did the installation will help you by contacting BDL.
There's some threads about Falcon belt failures if you do a forum search.

 

Yes did that and it seems to be a common problem with this product but it also says on their website that 1 inch belts are for show and custom use only so I have to wonder why it was put on a Touring Bike that was in the middle of a 9 month around the States Trip.
I will be happy if I get a new Gates Belt and a casket set so I can get it changed again when I need to which will probably be soon I think