Stripped spark plug threads.

[a. palmer jr.]

I've used the NAPA inserts before on VW engines with good results. Seems like I used red Loctite to secure them...

 

[s sidewall]

I like timeserts, they don't uncoil and stay locked in. They do cost when the buy the setup. Each size takes its own tool setup.

Steve Sidwell

 

[L34]

I used keen(key) Serts.

 

[Polish hammer]

I looked into the keen ones but with the hole being so big already I’m going to tap it for a m18 plug and see how it runs with a bigger plug

 

[a. palmer jr.]

I didn't see in this thread what kind of saw it is but on some saws it might be cheaper just to replace the cylinder with a new aftermarket one. That's what I'd do on something like a Stihl homeowner saw or something that is kinda common.