Due to the crank case leaking i'm rebuilding my engine. Here's what the pistons look like;

This is the rear cylinder;





This is the front cylinder;



The engine has done 115km, most of which was covered on a trackday in very wet weather. It was running on 30:1 premix with BP Ultimate 98. Main jets are 195 (rear cyl) and 198 (front cyl).

This looks like detonation to me, what do you think?
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After years of moaning about immigrants now i am one...

Thats what the stock 300 kit piston crowns look like.
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If I have to take the carbs off once more...

WOOHOO! That's good news indeed, i'd found some pictures online of pistons suffering from detonation and they looked similar to my photos so i thought i'd check with the experts before going any further.

Do the photos reveal anything else about how the engine is running? Or does it all look good?
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After years of moaning about immigrants now i am one...

Thats a 150 barrel !When i had dettonation , it looks more like sand blasting on the edges of the piston and the head , more on the exhaust side where the heat is .Sorry mate , never seen my pistons look like that before . Ps . I am not a gp tuner , just a plonker !

He has a 300 kit fitted.

Thats what the stock 300 kit piston looks like. The crown of them all look like that, even new.
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If I have to take the carbs off once more...

Mint, thanks for putting my mind at ease.
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After years of moaning about immigrants now i am one...