FWIW, I measured the top “sealing” surface of the original prechamber vs. my replacement. They are the same thickness. I can see what resembles to me a slight difference in the prechamber beveled edge that sits at the bottom of the hole in the head.
How critical is a pristinely clean (bright) sealing lip in the head (at the bottom of the threaded area)? Does it need to be bright? Would fine scratches affect sealing (mine is not but cleaning in there is hard and aggressive cleaning would be hard to do).
There’s definitely black residues where the leak was escaping up the threads.
I don’t think so, but do these fine gaps “carbon up” and self-seal?
My other last ditch option is to take a prechamber from my other 602 turbo and see if it seals better (since it would be the OE design and not the MB replacement which seems to have differences per gsxr)?