Another phenomena I have witnessed which produces symptoms pretty much as those described is the transfer bar axle pin rotating and sticking out away from the sideplate.
If the small bend in this pin has rotated away from being flat against the interior of the sideplate, it may be causing the failure to fire. Pressing the bend in the pin flat against the sideplate again and preventing it from rotating via a non-permanet adhesive or peening might fix this problem
|