for the first time yesterday I ran my Remington chainsaw model #RM5520R until the clutch got hot and I shut it down. I have been trying to start it this morning and the thing wont fire. I have checked the spark, it was a little carbined but I cleaned it off. I also took the cover off to the break and the saw bar and cleaned it out with compressed air. put it all back and it still wont fire. Why