Hey guys i have a 2008 crf250r and the other day i was at a local practice track and the bike started good and ran good for about two laps and then it started to bog and i just figured i was in to high of gear but i wasn't. the bike died two turns later. i tryed to start it back up but the compreshion was really hard and did not start. later that day i tryd again but after two or three kicks it got so hard that i couldnt even turn it over. when i got home i changed the spark plug. and it helped for about 10 kicks and then lucked up. so what is going on? is it bad gas? or eletrical problems? btw what should i be running for gas. i am running 89 pump.