I have a 98 yz400f that seems to have been loosing oil the last few times I have ridden it. Yesterday I checked it just before riding and oil was about halfway up the dipstick so I thought I must be somehow checking it wrong. Anyway, I thought it would be ok since I was only going to ride for about 30 min. I got into a bad spot that required me to walk the bike for a little ways on the way back home and just as I got out of that spot, the engine started sputtering a lot and backfiring a little. It did this for about ten seconds and then shut off. I couldent get it started again except every once and a while it would seem like it fired once of twice. Upon getting it back home, it still had too much oil in it and was full of radiator fluid but it still wont fire. It seems to still have compression and nothing sounds out of the ordinary except when I crank it, air blows out of some hose near the shifter.It may have been doing that before but anyway, I was kind of thinking that it may have gotten somewhat hot and the excess oil somehow blew past the rings and fouled the plug. I dont know a lot about motors so I dont even know if that is possible or not but what should I do?