I am doing a post on the modification of a 261 Husqvarna. I want the reader to measure squish prior to taking the saw apart. If you measure squish without cleaning any accumulated carbon off the piston you will get a less that accurate measurement of the squish. Normally this is done with new/clean pistons, so I know it will not be 100% accurate, I just need a ballpark measurement. Should I just forget this stop or can I add/subtract some nominal factor from the squish measurement to partially account for the carbon? What is your experience?