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03 crf450r piston problem

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okay guys i was doing my valves and decided since i had the piston apart i would replace the rings only not the piston since my money is VERY limited. i took the piston and cylinder out and found this. cylinder looks great just looks like it needs a rehone. no scratches or problems normal wear. the piston however has a small ding like whoever handled it before installing it dropped it. do you all think this would cause any problems. i do not have money for a new piston.

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and this is the cylinder i think it just needs a light hone.

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it really is not bad and does not protrude much at all. what do yall think?

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The ring land seem ok, you seem like you're straight broke...

When that piston turns sideways in the bore, it wont have anything to do with that little ding.

The ring moves freely in the land its probably ok. Id probably want to knock that little edge off with a file just to remove the little risen edge that would get hot if you were WOT across a lake bed or something...

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The ding won't hurt anything. If the piston measures within spec, I would run it.

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thank you guys for a quick response. how do you think the cylinder looks. there is very very light scoring where the piston must have been rubbing but i ordered new rings with the rest of my order the other day. i will file the edge very gently to remove the risen portion. do you think a light hone will be adequate for the new rings.

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thank you guys for a quick response. how do you think the cylinder looks. there is very very light scoring where the piston must have been rubbing but i ordered new rings with the rest of my order the other day.

It looks worn but you can probably get a little more life out of it. Hone it, then check your clearances. If it's within spec it'll last a little longer.

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ony thing it would add (and won't cost you any $$) is look into just scotchbriting the cylinder, wash out with soap/water till it comes clean on a white paper towel (careful on shop towel as recycled shop rags could be nasty). I have only honed (with diamond hone) when there were actual marks on the wall you could feel with your fingernail. Aluminum oxyde hone wont remove material, but from the looks of things just scotchbrite to remove any "glaze" built up in the crosshatch that is there to hold oil..

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I know youre broke and all that, but right at the top of the cylinder there's a wear mark where the ring is changing direction that makes me wonder about the wear on the pistons ring land.

You should measure the ring fit with the new ring (feeler gauge). Id also have that cylinder honed with a ridged Diamond hone just to make sure its still round and the bore is flat.

A decent machine shop should be able to do that for ya in about 20 seconds for 10 bucks.

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If you do decide to replace that piston I have a couple of used low hour 03' pistons for sale in the classifieds section. They be cheap! One OEM and one Wiseco 13:1 high compression forged piston.

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I know youre broke and all that, but right at the top of the cylinder there's a wear mark where the ring is changing direction that makes me wonder about the wear on the pistons ring land.

You should measure the ring fit with the new ring (feeler gauge). Id also have that cylinder honed with a ridged Diamond hone just to make sure its still round and the bore is flat.

A decent machine shop should be able to do that for ya in about 20 seconds for 10 bucks.

worst case then get a diamond hone, it is very probable that after scotchbriting the carbon above the ring line it will be perfectly smooth.. if you get a measureable ridge at that point, look to hone but that is just not what should be done 1st thing. Significant wear would need to occur to have a ridge at the top of the cyl. Im guessing from what this rider posted the engine has no where near those kind of hours, but need to wait and see.

My HUMBLE opinion is scotchbrite first before hitting that thing with a diamond hone that CAN remove material. Aluminum oxyde on nicasil, perhaps, but diamond hone should be a last resort from what we have found..

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