I'm in the process of tearing down an SR for rebuild, and I want to do as much of the job as I can myself. My question relates to measuring and gapping new piston rings.

As I understand it, the rings should be installed without pistons into the cylinder, about an inch down, and the gap measured. They should then be filed a little at a time until the gap is where I want it.

What tool is best suited to file the gap? I see Summit sells a few different styles but which type is easiest to use and achieve the best results? I don't plan on rebuilding a ton of motors so I don't see the need to spend a ton on a one time use tool if I can help it.

Also, what is a good gap size for a motor seeing ~18psi daily? I know too tight and there are problems, too loose and it'll smoke.