I have just taken the head off of my OS .50SX. The piston seems to be in good condition except for some carbon deposit. However, there was no gasket or seal between the engin block and the head. The bolts of the engine head were also not very tight. This engine has never been opened before. Do they come without a gasket between the head and the block?

Should I put a gasket there? How do I remove the carbon deposit?