The motor has frozen up since I last tried to get it started. Took off recoil starter and it pulls fine. Wouldn't start last time but would pull and try to start. Now, it won't pull at all. What can I do to diagnose the problem? I'm guessing the pistons are frozen so I have sprayed wd40 into the spark plug holes and left the motor laying on it's side. Appreciate your help. I'm a lost ball in the high weeds.