Hello guys, I‘m about to have my cylinder replated with Nikasil. What is the recommended piston to wall clearance for a 1974 YZ 125 with standard bore and cast piston. Many thanks. 

.0018-.002 inches for an oem piston

Original was chrome on a "74 yz125A. Be interesting to see how Nikasil lasts. I guess it's expensive to get plated.

Thanks. I finally found the information in an old repair manual and can confirm it‘s 0,04-0,045mm.
the cylinder is Noguchi and is the same as YZ that come chrome plated. Nikasil lasts much longer and costs around 300-350€ including removing the old chrome.