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Is this normal?

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Usually those type of marks come from the big end rod bearing coming apart or some other debris. If your piston is ok, then it was likely from a previous "incident." Someone may have changed the piston and smoothed out the head and re-used it. Check your connecting rod for excessive slack on the crankshaft.

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No not the orginal owner. When I wiggle the con rod,it moves slightly from left to right.

Is this head still ok to run?

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someone exploded a rotating assembly, slapped it back together and sold it. If your crank has no up/down play, or other noticeable crank issue....you could run that head again. Not optimum for performance, but unless ya want to replace it...might as well.

I don't know putoline, but I wouldn't worry about some color.

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Yeah that was previous damage from the big end bearing going. It looks as the head has been machined/ smoothed out so it should be fine. The question is how does the cylinder look?

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I'll be replacing the head the SXS one. Not to expensive. I'll check the crank again to make sure. Thanks for all your help guys :lol: Really appreciate it

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I'm no expert, but the cylinder looks fine. There's some slight rubbing at the front but I can barely feel it when I rub my finger over it

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Right. That head was damaged from either a piston grenading, or some component in the bottom end. Main bearing, rod bearing, etc. Check the main bearings for play. Side to side in the rod is fine, as long as there is no up and down play. I would be worried that any debris may have damaged crank bearings when the damage was done to the top end. If it were me, I would replace the head, but it will be ok to run if you must.

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I'm no expert, but the cylinder looks fine. There's some slight rubbing at the front but I can barely feel it when I rub my finger over it

A long as you can't catch a fingernail on anything it's good as long as it's still in spec (not overlly worn)

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Quick question whilst I'm here.

Is gasket sealant needed? Or can you manage without it?

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Do you need a gasket, at either the bottom of the cylinder or o-rings at the top? Absolutely.

Gasket sealant though, you mean like yamabond or something? Not when doing a topend.

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