I took my pred to the dunes this weekend and had some problems. She started fine,and would rev fine, but when I'd open up the throttle in gear it'd pop and backfire. My friend said that when it did it, it'd puff out black smoke too. It didn't matter what gear I was in, anytime I'd get the rpm's up and run at a constant speed, it'd pop. It felt like a misfire b/c the bike would "stutter". I have never experienced anything like this before. I pulled my spark plug and it looked ok, maybe a lil on the lean side, but not bad. My gas is good and I'm running a 185 main jet. I'm thnking of stepping up to a 190 and putting in a new plug to see what happens. Has anybody else experienced this?