Bike is an 06 SM, with buncha mods, 440 big bore, FCR 41 mm, full Yoshi exhaust, cams, some others. Relatively new to me (~1,000 miles, 22,000 on the bike) so this was my first oil change. Went riding on Saturday. No problems. Went home and dumped the oil, opened up all the drains (including the frame filter, cleaned that), put in new oil. Bike started right up, like usual (never has much trouble starting), let it warm up, then off for 3 minutes and check the oil per the manual. Oil level was fine. Go out next day to go for a ride. Leave house, go onto main street, gave it some gas, and it just starts sputtering and popping and lurching like it's starving for fuel. WTF? I did nothing that would even remotely cause this! It idles just fine, even goes just fine at partial throttle, but anything past partial throttle and it sputters and lurches. My first thought would be the main jet getting clogged, since it idles just fine but doesn't like partial throttle. But it was literally a before/after event - bike ran fine, changed oil, bike runs like shit. Oil change related, or strange coincidence, something else messed up at just the right time?