Also the fusible link the one attached to the post looks pretty burnt

 

^100%


It's good to have a set of thread chasers when working on engines to get good clean threads for a more accurate torque value.
Not to be confused with a thread tap. Chasers are meant for cleaning where a tap is more meant for cutting. You don't want to cut threads that are already established, it only weakens them.





http://www.ebay.com/itm/METRIC-THREAD-CHASER-RETHREADING-TAP-SET-M6mm-8mm-10mm-12-MADE-IN-USA-7PCS-/141524514835?pt=LH_DefaultDomain_0&hash=item20f384b813