Hi all. Just returned from a two week camping/bike vacation in Seaside Oregon. Had a blast and put on some decent miles. here is what happened. On first arriving at fort Stevens (where we stayed) I filled up at the local Fred Meyer in Hammond. Headed to campsite and parked bike for the night. The next morning, out and about riding and bike ran great until she warmed up, I noticed then as I was heading into Seaside with slow moving traffic that it was having a hard time staying at an idle, skipping and missing and popping (sounded like backfire but never saw any flames). I also noticed on hard accelleration while at highway speeds, it would cut out and hesitate when I turned the throttle. it then sounded like it was running on one cyclinder (lawn mower sound)., This was of course on a Sunday over the 4th of July weekend, so no dealers or shops around open...also, fyi-nearest HD shop is Boring Oregon 2+ hrs away. Parked her and walked around seaside with family for a few hrs. Started her back up cold and she ran great...until warm again and same symptoms. Tuesday ame and I spoke to HD mechanic over phone. he said bad gas and to just grit my teeth and run her out with some good premium. I did this and two fill ups later (well, top-offs) bike was running great again when warm. filled up using Premium at Cheveron in LongBeach and 5 minutes later...BOOM! same symptoms. Took me 1 1/2 tanks of Shell premium to resolve the problem and bike is running great again. Question?? What is going on? Bad gas or is something else going on here? Thanks. Oh, HD mechanic said not to run additives as it could screw up my o2 sensors.