I was doing a compression check with a friend about a week ago when on the fourth cylinder the starter wouldn't turn the engine over. We both assumed it was the solenoid/ starter. Since that time I have replaced the starter, charged the battery( new battery -12.7 v), found that someone in the past fried the fusible link, hit it with a hammer--no good results! The starter sounds like it is spinning, but the flywheel does not engage to turn over the motor. The flywheel isn't missing any teeth and will turn with the crankshaft. Is this a starter switch problem or can someone point me in the right direction? Thanks, Allan