i recently sent out my head to mx time and getting the seats cut and hoping it come back right. now my bike is continuously maintained by me and so far the only thing that went are my valves around 50 hours, give or take. its a 2004 and i noticed sooo many people have problems with them. i dont get it, is it a simple lack of maintenance? and i am going from engine ice back to honda racing coolant? is that bad in some way? and my last question, how long will my valves last if i got the seats cut and got faction intake valves.