retapped spark plug

[Camarozzz]

Is it possible to retap a second time on a 9-1/2 HP Johnson with an aluminum head? if so what do I buy as a spark plug insert and tap kit? The existing 14 mm 3/8 inch long insert sits very loosely in the retapped hole. I purchased this used and am hoping I can repair it by tapping a second time with a larger insert.

thx ahead of time

[boats.net]

Need to find insert same as one thats in it so threads will match.

[kregalmach1]

by insert are you saying helicoil you can use them just keep a good eye on it for a wile