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Ball Hone size / Grit

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Whats the proper ball hone size and grit to do a 250 cylinder. Im putting in new rings and would like to hone it a bit to break the glaze. :)

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10% smaller than bore fine grit is what I use....available here....

Flex Hones do a seach for flex hones

Just enough to remove glaze.10% smaller than bore gives a real light fit to the hone.

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Remember your only honing for about 5 seconds. You don't want to remove the nikasil, just scuff it.

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Remember your only honing for about 5 seconds. You don't want to remove the nikasil, just scuff it.

It's actually a Thumper Racing 270 cylinder, it's iron. Im just putting in new rings because the original rings didnt seal well and Im burning oil and smoking a bit.

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It's actually a Thumper Racing 270 cylinder, it's iron. Im just putting in new rings because the original rings didnt seal well and Im burning oil and smoking a bit.

iron liners....... :)

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10% smaller than bore gives a light scuff you want.3.5 is way to big and would agressively hone the bore .

If it's 10% smaller it wont even touch the cylinder walls???

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Correct, but when you spin it in a dril it expands. A tight fit will damage the nikasil or the original hone marks.

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It will touch lightly....the way the hones are made....they are abrasive balls on the end of a stick that is meant to flex...hence flex hones.In otherword when you buy a 2.75 inch hone you will receive ...say something that measures 3.5....when you place it in the bore the bristles allow it to flex to it intended diameter.I'm unsure about an iron liner, but on nikisil you use 10% smaller than your bore to acheive a lighter hone fit necessary for nikasil.If you purchase a hone sized 10% smaller than the designed bore...it will fill the bore but with less pressure because of the above reasoning.

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Just take it to an engine builder....they can do it in less than a minute....also heard of some using scotch brite pads....dont know though :)

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I bought a 3-1/8" flex hone (320 grit) for my stock cylinder (CRF250X), just to break the glaze. Now you've got me thinking it's too big. I haven't tried it yet. I thought the 10% smaller size was just for the Kawasakis. :)

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I bought a 3-1/8" flex hone (320 grit) for my stock cylinder (CRF250X), just to break the glaze. Now you've got me thinking it's too big. I haven't tried it yet. I thought the 10% smaller size was just for the Kawasakis. :)

The 10% under rule is just for older electrofusion Kawasaki two-strokes which tended to tear the plating at the port edges. Electrofusion was a horrible plating method for dirt bikes.

You can run a bore sized 320 grit aluminum oxide ball hone through a nickel bore till your drill wears out and you'll do nothing more than scratch the surface peaks. Plated nickels bores are so hard we have to use diamonds stones in our Sunnen horizontal hone to move any measurable material. You wont hurt a plated bore with a ball hone unless it was already compromised. :)

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Does anyone know where one could get a ball hone at? I looked at the link in the previous post, but thay do not have ball hones.

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Does anyone know where one could get a ball hone at? I looked at the link in the previous post, but thay do not have ball hones.

Go to http://www.mcmaster.com/ and go to page 2499. I used the 320 grit 3-1/8" flex hone and it worked beautifully clean the cylinder. If you can't find the page search for 'flex hone' as 'ball hone' won't come up.

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also heard of some using scotch brite pads....dont know though :)

I read this in a recent magazine; it seems like I read it in MXA, but I couldn't find the article. They said that you should Scotch-Brite (not a ball hone) on a Nikasil liner. Anyone else read it?

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I also read that in MXA, they said that a ball hone does close to nothing on a modern cylinder. And the only thing that cuts it, is a diamond hone. and added that its verry hard to find someone with one. MXA says all they use is a scotchbrite to clean up the cylinder. and they dont worry about scuffing it back up I guess......................... My question is, Will a normal ball hone scratch it up enough to produce just enough cross hatching to let a new set of rings seat in properly?

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