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Cylinder Scored

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Hello, First time posting on TT. Very resourceful site. Anyway I have a 2004 yz250 that i am doing a top end on. The top piston ring split in half and very lightly scored my cylinder wall. I dont really have the money to have it replated at the moment. Can i run it as is? I can barely see or feel the score. Sorry if this is a dumb question........

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If you are really strapped for cash... the short answer is "yes".

Make sure there aren't any high spots where the scratch is on the wall.. throw in a new piston/rings and go ride the bike! It may not be 100% but it will work as long as the scratch doesn't have a raised edge.

Pictures would help!

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I was unable to get a good picture of the cylinder but i can see the cross hatch pattern throughout the cylinder.The cylinder head is also a little pited on the intake side. I think im gonna run it and replate or replace it next time i do a top end. What is the worst that could happen?

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If it catches a finger nail, thats a bad thing. It could take out the ring(s) and then you will be spending more money again! Unless you want to keep dumping money into it, fix it right the first time! (trust me, you will save headaches in the long run!)

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The least that can happen is that it will run ok and you may never notice a difference. The worst that could happen is that the ring could catch a high spot and destroy the whole motor. If it was a 125 I would say don't try it but the 250's are a little more forgiving but you have to ask yourself why did it screw up in the first place. Are the marks horrizonal or vertical? Vertical lines tend to cause a loss of compression depending on where they are. Horrizonal lines have more of a chance for a ring to hang up and really screw up things fast. If you can't feel the marks with scribe you should be ok. However if you can feel a slight bit of resistence when going over the mark you may be in for trouble. Hone the cylinder and try again, if then you still seel it you have a 50/50 chance of survival. Do you feel lucky?

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