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Over size my piston?

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I have a 2000 250mxc and the motor went in it. My question is, can you bore these motors out to say .30 over? And where would i find an oversized piston?

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Yes my cylinder is scored. Pieces of the needle bearing blew by the piston. Thought about just honing it and putting a stock sized piston in but i like to figure out what all my options are before doing things. If i were to bore it out does any one know what piston might work? ie. ktm 300 same era...

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"Don't bore it out unless your cylinder is scored. You will regret it"

Out of curiosity why would i regret it? Ive dond a few hotrod cars and "theres no replacement for displacement" naturally i assumed the same concept applied in dirtbikes...

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I have never heard of any one complaining about there engine after having it bored and plated.

Not hard to get the proper piston all of them offer proper oversized. Usually you buy the piston and send it in with the ccylinder then they will machine to the correct size

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.30 over isn't going to create a power increase you are going to notice. Better off having it sleeved back to stock then you can use a stock piston. Keeps it simple.

 

If you are looking for power gains then go with a 300 cylinder kit (if they make one for a bike that old?)

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Ive been looking for a few days now to find the proper oversized piston for my bike online but havent found anything... Thats why i asked if a 300 piston might work just not sure if the hight from the wrist pin to the top of the piston is the same.

Thanks for the info by the way.

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Not really needing power gains ( i have the cr500 for that) im more just looking to get the ktm running because i love riding it sooo much

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Just get it replated to stock size. Any other route is gonna lead to trouble and expense in the long run,,,like you said,,,no cast iron sleeve.

Edited by ohiocoalminer

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Sounds good to me.

Hey, thanks guys for all the input its really appreciated

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A cr 500 does not have nikasil cyl and can be bored over.

The KTM cyl is hard coated ....send to RowerSeal in PA. 866 845 1531

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Ahhh,,,low tech is good tech sometimes,lol. Thats why the ol bikes like that are still servicable today. Ive heard power seal is good. I always use millineum.

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Sleeves are good, but imho nikasil is great. Its nice to go back to stock bore and go through 5-6 pistons before replating . A-b sized pistons are a wonderful thing.

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.30 over is a substantial oversize considering there is only a difference of .216 between a 250 and 300 . so that would be noticeable in power if even possible  .030 oversized would be more like it   

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Woops ya i did mean 0.030 lol might try cleaning up the scratches with some emery cloth and go from there. Thanks again for the input, im so used to forums being not very helpful.

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