I filled up my tank yesterday and rode about 20 miles. I washed the bike this morning - gentle water, nothing extreme. When I went out for a ride this afternoon I began bogging when under load. It bucks like a bronco! If I gradually roll on throttle it seems fine but if I twist it hard it goes buckety buck. I thought maybe the gas wasn't great so I put in a can of sea foam, and I sprayed carb cleaner down the vent tube under the gas cap. I waited a while, and drove around a bit. No change. Any thoughts?