like people have mentioned, boring out is done to clean up a damaged cyl sleave. To big bore it you need to have the 200cc sleave cut out, the cyl machined, and the new "big bore" sleave installed.

Do your self a favor and reread how to measure. .010 is used for a normal clean up, .020 is used to clean up a badly trashed cyl. At .2 you are .05 short of a 1/4 inch, and .8 is .05 over 3/4 inch.