OK, you won't believe this, older in new condition, maybe 1997, McCullough 3516 chainsaw, don't start, maybe sometimes in a blue moon, took off the muffler, starts every time, muffler is on, won't start, the muffler isn't clocked up, its like new, clean screen and together right, it won't go together wrong, so I took the guts out and just put the case on and it starts and runs fine, comments please... thamks richard
