2000 YZ250 not starting

I had my 2000 yz250 running and accidentally left the petcock off and it shut off. No matter what I can’t get it to start up again. I have spark
( even switched out a new plug). Good fuel, the petcock works and fuel gets to the carb. I have good compression, yet it still does not want to start. I’ve tried everything I can to get it to start and it just doesn’t want.
This is normal procedure for me .. turn off fuel , let run out . ALL my bikes since I was probably 10 yrs. old ..

Try draining fuel bowl , looking for bad fuel , water , do you have a spark tester that clips on spark plug ?
Double check spark plug , kill switch , my CRF 250 R vibrated out fuel adjustment screw , I never checked that , did'nt notice . Left it parked for about 3 months , just took it to a buddy today when picking up some parts to machine for him , when I returned parts he showed me what happened . Glad it did'nt happen out in the trails 10 mi. out ... Must be something simple . Check compression ...