i was fixing my grandfathers lawn mower. its a murray with a briggs and stratton 4 stroke. the sparkplug hole stripped and the sparkplug shot out of the head and made a hella loud noise upon ignition. i dont know if replacement heads are made so i was wonder how good would it be if i had someone weld the head drill it and retap it for a sparkplug? will weld hold up to the temperatures?