Hello, anybody seen this before? My '09 Streetbob sits a lot due to medical problems(mine, not the bike's). I just had the fluids changed because of the time interval, not the mileage. The bike has always run hot, at least to me, so I asked the dealer to put in straight 60wt dino instead of the syn3 as this has always been a winning combination for all my carbureated bikes. I took a nice ride yesterday and the bike performed well, got a little warm toward the end of the ride and backfired a little, so I just figured it was a wash and I saved some $$$ on the fluid change. Today, I ride the bike to work and back(about 45 miles) It bakfires when I start it, sounds like I have some predetonation, and the gas mileage is BAD. The only thing that has changed is the oil.The book says I can run 60wt in ambient temps above 80 and the only time it gets below 80 in July in South Florida is at 3 in the morning during a nice rain. I'm just about ready to drop the dead dinosaurs and put a full synthetic in, but I'm finding it hard to believe an oil change is causing all this. Any ideas? Thanks.