I am trying to install a temperature sending unit on my 1995 Mariner Tracker Pro 60. It just has one of those on off temp switches mounted to the head that sets off an alarm if it overheats. The Mariner manual says that you can install an optional temp sending unit below the number one spark plug on the head. There is a drain plug or head plug below the number one spark plug that has a star shaped female indention. I tried a T50 star head driver in it and it fits a little loose but it's the only size that seems snug enough to try and remove the plug. My problem is the plug won't move...it's frozen. I've tried WD40 and liquid wrench but I don't know if they're getting into the plug threads to loosen it because it's still stuck and I don't want to strip out the plug. Anyone have any suggestions on how to get this plug out so I can install a temp sending unit?
Thanks!
Thanks!