I am attempting to remove two very reluctant spark plugs. They have not been shifted for over ten years and I suspect they are stuck with a mixture of carbon and burned-on oil. I have no reason to suspect they are cross-threaded, and they are the right length for the head so there is no carbonised lump at the chamber end as can happen when a long reach plug has been wrongly used in a short reach hole.
A modest degree of brute force and a well-fitting socket having failed I wonder if you chaps - who have doubtless come across similar things with some of your old iron - have any recommendations as to a good solvent/penetrant to help ease them free.
Thanks in advance,
Gyppo