Thanks for all advice. Lots of good info. Parts for Bultaco are still pretty easy to get. I'm not to worried about boring the cylinder, this was the first time over. Got lucky there. I just ordered a specially prepared mikuni carb so I'd like to start this year at square one. I'm going to do a light clean up with the scotch bright and new rings. CharlieT who sells that brush hone I'd like to have one for future projects. Thanks all for the help.