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Need Help Fast!!!!! Pw50 Advice

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I dropped off a jug for a 94 pw50 to get it bored .25 over. Have to drop off the piston in the morning to finish bore and hone. (yamaha .25 piston)The shop i bought the parts from recommended boring clearance to .005 to lessen the chance of seizing the piston. The guy seemed very knoledgable...just wondering if I can get a couple more opinions. Anyone know what clearance is actually called for? Thanks

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well .25 is not alot to began with and the compression unless you are milling the head also is low,

i would go with standard bore only not .005 more, usually the honing depending on what they use will bore the cylinder bigger itself after boring,

here is a sentence i cut out of a article on performance boring,

They will leave .003˝ to .005˝ in the bores for honing, and then use a torque plate when they are honing," says Stratton

and here is another one

The next step is honing. Boring leaves us straight, round and square cylinders, but without the proper cylinder wall surface or size. Honing will remove the boring marks and the remaining fractured metal and create the proper crosshatch pattern. The first step is honing the cylinders with rough stones to remove material until about .0005 of material is left. We change to finer grit stones to finish size and leave the proper crosshatch.

just bore actual size and you will be fine a good machine shop will take care of the rest in honing when you drop it off :)

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