Going from .010 to .013 cylinder

[pwizl]

I'm rebuilding an '81 engine and in the process of teardown I found that at some point the bike sat with water in the cylinder causing erosion on both cylinder walls. I can get a set of cylinders off of an '82 for $40 that would just need a light hone and good clean up of the exterior. My question is this, the cylinders off of the rebuild engine are marked .010, the replacements I found are .013, will there be any fitment issues? I'm particularly interested in the cylinder to case fit. Do those numbers only affect the INSIDE diameter? Will there be any issues with using the pistons from the .010 cylinders. I know it's only 3 thousands difference and I wouldn't think there would be any problems, but this is my first motorcycle engine rebuild so I'm not sure. I believe the stock bore size is 75.013 - 74.960, which is a pretty big range. Any help is appreciated, thank you in advance.

 

[XSLeo]

The 010 and 013 are the bore size. the bores are always 75.xxx, the three digits on the sleeve are the xxx. The 74.960 you list is the size of the pistons.
The piston to bore clearance is the difference between these two numbers. 75.013 - 74.960 = .053. The clearance spec is .050 to .055 mm. The 53 is pretty much center of the spec.
This only applied when the parts were new. You need to measure the parts you have and calculate the clearance you have now.
If you don't have the tools or skills to measure these things, most any machine shop will have, they won't charge much. Once you get the measurements then you can decide just what you need to do.
If your bores are to worn for the pistons you have then a rebore to the next oversize is needed. If you do this get the pistons first. Once you have the pistons get the cylinders bored to match the pistons. If you get the cylinders bored first the piston you buy may be too big or too small.
If your piston to bore clearance is ok then a new set of rings may be all you need.
Leo