I was trying to figure out what kind of thread size the OS MAX FS 70 engine uses for its exhaust connector port. I am talking about the following (green circle)
I could not find this in the manual, just the replacement parts but not what the thread size is. I have tried to use my measurement device and it seemed to be a 10mm hole, however using an M10 screw, it just slid into it like nothing. An M12 screw was too big. There are no M11 screws where I am from. I suppose it might be an imperial thread size, and I have absolutely 0 experience with that.
Does anyone happen to know what the thread size for that exhaust port is?

