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Cylinder Lines

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Hi All,

Put a brand new top end with cylinder that was freshly replated went for a spin around the block.. BAM... stator side crank bearing seized.

Pulled the top end off... looks good, except I have all these black lines running through it. They dont feel rough, they wont buff off with scotch brite. AND the crosshatch is running through them almost as if when I plated it, it came back this way and I just forgot.

Take a look tell me what you think. again if i run my nail over them it doesnt catch or anything.... strange..

IMAG0430.jpg

IMAG0428.jpg

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this same thing just happend to a guy i know... except his piston skirt blew up on him, you more then likley installed the piston the wrong way. if it has an arrow, then the arrow is supposed to face the exhaust. if the piston says in, then that part is supposed to face intake.

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this same thing just happend to a guy i know... except his piston skirt blew up on him, you more then likley installed the piston the wrong way. if it has an arrow, then the arrow is supposed to face the exhaust. if the piston says in, then that part is supposed to face intake.

Thanks for the response.. the piston was facing the correct direction. Very peculiar.. almost wondering if the replating process left it looking like that. as the cross-hatch runs through it. not the other way around...

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nothing wrong with that or i mean it will not hinder running of the engine, iv been running a cylinder with a cracked ex bridge for the last 3 months and the plating has come off the top of the ex port & she still runs great, the engines ready for rebuilding in a few hours so ill just run it untill it pops,these engines can handle way more abuse and damage than most people think lol

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Are there witness marks on the piston? I had similar marks after a rebuild but they were located at the ring gaps. I think that it is material deposited on the cylinder from either the piston or the rings. The plating is harder therefore it can remove material. I would imagine that they would become less pronounced as the bike runs.

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