Okay so I bought a 2006 400ex and the starter clutch/one way bearing went out of it while I was riding it the week I got it. Bike ran great up until the one way bearing went out. So I replaced the bearing and flushed all the metal shavings out from the motor and everything. Put fresh oil and filter in. But now for some reason it won't start. I have good spark and good fuel. So I tried a little bit of starting fluid. And it fired a couple times then nothing. So the next day after draining the bowl and trying to start it again I sprayed more starting fluid and after a few minutes of cranking it backfired a few times. (Not sure it would technically be backfire but it popped out of the exhaust a few times loudly.) haven't tried anything else since then. Any help would be greatly appreciated.