Keeps Blowing Spark Plugs Out

[Cub 800]

I think it might be Pissed at me.

So I've had this tractor a couple years without any major problems, But about a month or so ago it blew out the spark plug. it seems someone had already put a timesert in it. I put some green locktite on it and screwed it back in and it held. But cause I knew it was going bad I bought another head off fleabay.

new head looked good, so I beadblasted it and sanded it flat, then ran a plug cleanup tap in, every thing felt good.

Next time it blew the plug I decided to change out the head......
put the new (used) one on and after screwing the plug in I remembered I did not check the plug gap. unscrewed the plug and the second time I put it in the threads just came right out!!

So I took that head back off and took it to a guy to have a timesert put in it.
( the old head had the threads gone and it was already big from having a timesert put in it)

Put it back together and I'm Golden.

Ran it two or three times, I only need it to cut the rough side yard and an area behind the house that doesn't have to be too purty. So today I get it out and go to start it and THE PLUG BLOWS OUT AGAIN!! WTF?? .....takes the timesert with it!!

So I have the old head I can have tig welded up and redrilled then machine the plug surface flat, OR bite the bullet and try to find a NEW head, in spite of the cost I am leaning this way.

Now this is no high-compression pulling motor is just an old 8-hp k-181

This all started after I moved the tractor out of the garage because I needed the space to rebuild a Porsche motor I am restoring. so the tractor was moved into my motorcycle trailer as a temporary home... better than leaving it outside.

First the coil went, then it blew the mower drive belt, now this...

I think its PISSED at me.