It's not uncommon and it can take 2 or 3 fills before the issue corrects itself. Best piece of advise when getting gas. Don't ever fill up when the tanker truck is dumping or within and hour of it either and try and stay away from the obviously older gas stations.

 

Agreed, Watch Guy. I just so happen to work in the petroleum refining industry and understand the issues with trucks unloading at retail gas locations. If the tanks at the retail station are low, the new delivered product will agitates and stir up debris, wax build-up and general crap off the bottoms of storage tanks. Need to allow time foer this to settle out.

Also, water routinely collects in storage tanks at retail locations and needs to be drained occasionally. Especially, if a retail distributor did not drain water out of the tanks prior to transitioning to E-10/ethanol gasoline it could present the problem of phase separation. Ethanol has an affinity to water whereby the water will literally pull the ethanol away from the hydrocarbon gasoline. If this has occurred along with the scenario above, one could potentially get some water along with the gasoline when you fill-up. I'm probably on my 3rd tank of gas since my issues began.

Anyways...I am going to go down my checklist and see if I can't solve the issues through process of elimination.

Thanks!

 

Wanted to follow-up with everyone who provided their input regarding the issues I was having on my '03 Heritage Softail coughing on occassion and popping out the exhaust on decel. Seems that one of the rubber nipples which terminates one of the vacuum lines coming off the EFI as deteriorated. This part appears to have lost its seal/vacuum and was allowing air to get into line. Replaced the rubber nipple for about $3. Also, buttoned down some bolts on the flanges from exhaust pipes. Don't rightly know how much each of these items were the culprits of my problems. At the end of the day...something tells me that some bad gas may have been part of the problem also. Don't have anything to base this on...but have run a couple more tanks of gas through the bike since my initial issues.

Just ran the bike on an approximate 100+ mile run today without any coughing/missing, etc... Encountered some very minor popping on quick decel from very high speeds a time or two.....but nothing like I had been experiencing. And, I understand that, considering the bike is 7+ years old and 31,000-plus miles, a little popping out of the Screamin' Eagles slip-ons are customary.

Thanks to each of the Forum participants who provided input/ideas in helping solve my issues.

 

Try the intake manifold gasket leak test with an unlit propane torch while the bike is running and see if the idle changes.

 

Another follow-up on my missing/coughing issue along with the popping out exhaust on decel.....Just returned from a ride up the Blue Ridge Parkway. Did approx. 1,200 miles total over 4 days. I did take the bike back into the Harley dealearship prior to the trip, i.e. new tires and to check for exhaust leaks, etc... for popping.

Unfortunately, the bike missed/coughed about 5-6 times during the trip. The popping wasn't nearly as bad as before but still not satisfied. The Tech at the Harley dealership stated that it is not uncommon for the SE II slip-on's to start popping a little after they get some years (7) and miles (32,000) on them. Perhaps so, but I get off the bike one day....don't ride for a while....get on another day and the missing/coughing/popping out exhaust on decel begins all of a sudden out of the blue.

Again, for 7 years and 30,000 miles, the bike ran like a champ. Still do not have an answer why/how the missing and popping started. Thought the culprit was bad gas, but that was ruled out over such a long trip and burning through a number of tanks of gas. Missing/popping is not as bad, but with it happening once....that's still once too much!

 

Do you have stock spark plug wires on the bike or aftermarket? My wife has a 2003 Heritage and around 25000 hers started misbehaving like yours. After numerous days at the Harley shop, an EFI replacement and a new Power Commander which didnt fix it. We took it home and noticed that one of the wires had a burn mark on it. Turned out that it was arcing against the engine. Replaced them and no worries since.

 

Still have the stock spark plug wires. I'll inspect and make sure they're still in good condition. Thanks for the input.

 

Got a new to me 01 Ultra classic with the same issues. 69K miles.. I'm taking notes...!

 

I have a 04 heritage that started popping after I washed it. What could have caused this need help.