Already tried this in another forum and didn't get any replies so I'm trying here. I bought an 02crf450r about a month ago(probably a stupid thing but I'm a guy who dived into things head first) without much experience with engines or bikes but I did have a ttr230 before it. Well I haven't been able to ride it much although I did change the oils, and fork seals, I rode a short while after that and everything was fine. Last week the air filter I ordered came and I replaced it for the original (which obviously hadn't been changed in a while). And after that I got some time to ride and jumped on it for a few. About ten minutes later it started choking on me, so I figured I was low on gas and filled it with vpower (highest octane rating at the pump) Was really hard to start but when I did get it started I could nurse it into running(though very choppy). However something was obviously very wrong so today I drained my gas and filled it back with fresh vpower figuring it may have some water. It started and seemed to be fine but again after a few minutes it started choking and died and did not want to start and when it did it choked out again after about 20 feet. I would really appreciate some suggestions here I am out of ideals, I don't know what the hecks wrong with it.