I filled up my motorcycle last week a few times at different stations and noticed some stuttering problems. Went through the electrical system and didn’t find any problems, cleared up after a few days. Then filled up a full tank of premium gas at this Sam’s Club and got a few miles down the road before it started backfiring like crazy and stalling in traffic. Limped it back home and have siphoned out the bad gasoline. Smells like a old locker room. Never again will I get gas at Sam’s club.