Thank you to everyone who advised us on opening the cowling and changing our spark plugs! That went smoothly, however, when we were ready to take off it would not go into neutral to start. After hours of work & testing - we have determined that the cables are fine. We were also able (when the cables were undone) to start it. It started and ran like a dream. A Mercury dealer told us that he thinks the shift fork needs replaced. He says that it is impossible to do this ourselves. Would everyone agree with this? We have a 1974 Mercury Outboard. SN 3808765 65 hp -Thanks!