Originally posted by pelos
I have been living so long with the nightmare of ruining my wonderful NSR12S3... now is happened.
Maybe I used a too hot plug (6TC with 18C temp and 16%nitro) or maybe I was too lean (about 4 1/4 turn out HSN).
The plug broke and filament scratched piston side. Top of piston is also sandblasted. See pics
The motor run about 8/9 liter.
What can I do?
Seems like the engien is overheated .