125-200cc i stuffed up!

Pulled 165 apart today to send off to Walt for repair n replate.

Not sure if the pitting on piston edge n head is from wen she blew the oring n spat the coolant as was ridin sandy singles at full noise before I stopped n noticed coolant pissin out. Wat yas rekn? Is that standard overheating look? Can c a small indent in piston too.

Mite go 1/4 richer on rod n PJ wen put it bak together!

It's only fractionally hot there seen far worse.
Yup a fraction more on pj an you should be good.
That could of happend as result or when your exhaust o rings got melted out.

Nah wrong bike mate that was the 300. Orings seemed to have lasted a full 5 hours of racin plus an hour of trail riding with young fella today. No rattling pipe so far. Did put sum rtv over orings before installing dunno if that made a diff.

Anyway this is the 165 piston/cylinder that chipped the plating n wore a small gap in cylinder wall leading to oring failure. Wat causes the indents in the piston/head? Jus excessive heat? Looks like sumthn was bouncing around in ther! Inside of piston looks brand new

Yeah it's just too hot that it starts eating the ally at exhaust port area on piston as I say I've seen them much worse so your slightly lean.
Ahh right see I would of thought the 165 would run hotter than 300... fingers crossed the 300 exhaust orings stay good.