my 2000 cr250 was running a little strange and blowing blue smoke today. it seemed to be running okay while i was riding it, but it was hard to start even when warmed up and had a hard time idling. the idle was surging and had a strange, muffled sound. it did not sound tinny and healthy like usual. it was smoking white with a tint of blue. my tranny oil was pretty low and dark grey. bad crank seal? thats all i can think of that would cause this. i can change the seal without splitting the cases right?