So I picked up a 2004 XR250R from a friend this last weekend. It had been sitting for at least 1 year if not more. He did not drain the gas out of the carb and the last time it ran before he parked it. SO when I picked up the bike I changed the oil, changed the spark plug to an iridium one, changed the air filter to a uni, drilled the baffle, pulled the snorkel, and completely took apart the entire carb. The o-rings seemed to be in pretty good condition so I reused them and I changed the jetting to 48/140. I put the carb all back together but since I was working by headlamp due to no light in the garage. I put the float upside down. So after trying to start it for a while I figured out that there was no fuel in the carb. So I pulled the float bowl and flipped the float to the correct position and set the screw to 1.75 and also tried 2.5 turns out. The manual said 1.75 was stock but when I pulled the carb it was 2.5 turns out so I tried both. I put the bowl back on, turned the fuel on, put the choke all the way on and spent all last night trying to get it to start. I got one small backfire and nothing else. I tried bump starting it several times with no luck. I checked the spark plug and it seemed a little wet but was sparking. I don't know what could be wrong. There seems to be plenty of compression since the bike only has maybe 150 miles on it. The only thing that I can think of is that when I put the float in upside down I messed something up or my jetting is way off. I still plan to grind the header but did not make it to it due to it being dark. PLEASE help I am supposed to go riding this weekend, and I don't want to have to sit there while the wife does all the riding. If you think it is the float level how do I fix it the repair manual shows a float height measuring tool that I don't have.