So yesterday I'm changing out my spark plugs. I get em all out, then put new ones in. I get all the way to the last one, and it won't go in. I'm trying for about 30 minutes, to no avail. I finally determine that the hole could possibly be stripped. What should I do? Or what needs to get fixed here? Any ideas?

 

If the plug won't start into the threads maybe you just need to chase the threads in that hole with a tap. Put grease on the tap to catch the metal shavings, use a shop vac to clean 'em out. Be careful to get the tap lined up properly or you'll screw it up & have to read the next paragraph...

If the threads are stripped out, then the plug just spins. You gotta get a Heli-Coil insert or something like that to fix it. Tap it out to a bigger size & install the coil insert. They come with instructions.

 

Thanks JimBlake!