Plugs backing out

[evaneyeball]

So on my new build I rode it yesterday and I had my plug back out a little i wasn't worried about it I just figured that the powder coat under the plug that was pushing it out. I dont think it sucked anything in because it was barely out it was just not snug anymore. But then today we went for a small ride not anything crazy just playing and I got back (my brake line broke) and looked it over and it had happened again so I read up and I found that it might be detonation but at this octane and with the different jets I ran yesterday and today( I swapped them to fatter yesterday when it happened then I went back and it happened today) so I dont think it was detonation unless my timing is messed up wich arlan set the timing so I dont think it was that. Or it could be that the threads in the head are loose and now that I'm thinking about it the old plug that came in it had some loctite on it so I'm thinking that if it's not detonation then it's probably the head. That head wasn't going to last anyhow but do you think that that is the problem? I have pictures of the threads I will post soon

[evaneyeball]

And when I first noticed it today the plug was still actually tight but there was some black residue around it so I think that those threads are bad. It did have a new plug in. These are pictures of the first time

[Jerry Hall]

Show us many views of the spark plug porcelain tip, center electrode, ground strap, and a well lite view of the porcelain from top to bottom.  Show us a view of the top of the piston with it at TDC.  Show us a view of the combustion chamber and squish band of the head.

[evaneyeball]

I haven't taken the head off and dont plan to this weekend im still at the dunes but I am going to call arlan tomorrow and can go take more pictures.

[evaneyeball]

These are the pictures I can take right now

[evaneyeball]

Any opinions? I just want to know how screwed I am

[broken1]

Start by carefully & completely removing all the powdercoat from the plug seat area. It looks like some of it is ready to break off & fall into your fresh cylinder... After getting that cleaned up put in a fresh plug & get it seated properly & take it for a test ride.

[evaneyeball]

I did remove most of the powder coat after the first time. The pictures were taken the first time. And when I thread it in about half way it is super loose like you can pull it up and down and side to side. If that makes sense.

[atvmxr]

Im having this issue in one of my Rs and my sons RM85 too.  maybe Im just not getting the plugs tight enough.  Running 112 race fuel

[F-Red]

You need to tighten the new plug well, to crush the washer. Make sure the threads in the head are good too.

[The norm]

I would recommend looking up the torque spec for the plug and tighten it to that spec. Probably going to be in the 10-15 ftlb area. I have never had a plug back out, but as a young man I stripped a few out lol. Your plug should not rock back and forth in the threads or move up and down. Sounds like the threads are compromised and you may need to either get another head or get a helicoil kit for the head.
Loren

[The norm]

I just looked at my manual! Spark plug torque is 15-20 nm or 11-14ftlb. It may seem silly to torque a spark plug, but the reason I do is it eliminates the possibility of ruining the threads or in your case the plug backing out.  I also torque the oil drain plug for the same reason. It protects the aluminum threads and reduces the risk of oil leakage.
Loren

[evaneyeball]

I do plan on calling Arlan today but I do think that those threads are screwed up and the dome part is also screwed up but I will call arlan

[Hawaiiysr]

plug blowing out could be a sigh of detonation. hopefully just junky threads

[evaneyeball]

I think it's a mix of junky threads and  mabey detonation because I dont know what compression I have