M444 Spark plug spinning in seat Onan CCK 25HP

[GlennsM444]

I finally got my M444 up and running. Things were going well for a few hours and then she started cutting out. I thought it was a carburetor issue again but when I looked under the hood the front spark plug (right if looking at flywheel) was spinning in its seat and leaking air. I tried taking the plug out and to no avail - it just spins loosely in its seat. I removed the head and it appears the plug is bolted tightly into a "sleeve" around the thread of the plug that is loose in the head. I tried yanking the whole thing out with a vice grip and to no avail. 1. Does anyone know, is this sleeve usually found in Onan heads or is this some type of "re-thread" job that someone did over the years? 2. If it is in fact a manufacturer sleeve, is it steel or aluminum? if it is aluminum I might ask a friend to tig weld a bead around the base to seal it up. gc

 

[OldMachinist]

Sounds like a spark plug thread repair insert. If you try pulling and turning at the same time it may unscrew. It could be made from aluminum or steel depending on the brand. Google “spark plug insert” images and you'll see.
Since it's been repaired already you'll need a oversized insert. There are places that sell them. http://www.timesert.com/html/bigsert_sparkplug.html

If your friend is real good with the tig you could have him weld the hole up and then you can drill/tap new threads.