my wifes new sporty did something similar Sunday. Sputtered like crazy then quit and was fine for 2 days. Yesterday it finally gave up running all together..........coil was bad.

 

Very good possibility. I filled mine up and let it sit in the sun for a while and had the same problem. Cleared up in about a quarter mile.

 

Zoinks! I just posted a thread about my 88" doing the exact same thing. I accidentally left my gas cap at a gas station after fueling up this past Sunday (it's under that chrome lid and I just forgot to put it back on). Rode it about 3.5 hours with no cap. About 100 miles into the ride it choked down on my and I could only do about 45 mph. After about 6 miles, it cleared up. But tonight it's been coughing. Weird so many of us are having similar issues.

 

Took her out last night and had the EXACT same thing happen. Since they were open until 7, I decided to head to the dealer and ask their opinion. The service manager asked if my engine light ever came on (no). And then said the best he could do is schedule an appointment to look at it. Earliest they could get it in is July 8th. I was planning a weeks vacation with a lot of saddle time next week too.

After I left the dealer, I rode for another two hours (combination highway and stop and go light to light) with NO problems at all.

When I was done for the evening, I filled up at a different station and took the advice to add a couple ounces of Sta-Bil to the tank.

We'll see what happens when I take her out tonight. Got my fingers crossed that it was just a bad tank of gas..

 

Definitely Bad Gas. No more Mexican food you you!!

 

Happen to me once before years ago, too while I was getting up to speed on a ramp to the interstate. I thought my motor was coming undone. I had the throttle turned all the way and dropped from 65-55-45 and kept going down until I pulled to the shoulder. Turned the motor off and back on and motor ran fine. Stop at the Harley shop at the next exit and the guys at the service counter asked me if I had just fueled up. I told them I did earlier that morning. "There's your problem...water in the tank." I asked them if there was anything I should do and they said not to worry, the water blew through the motor...that is what I experienced.