I have been intriged with the process and proceure of Piston/Sleeve resizing, Being offered in the rc car world....I had 4or5 done , that which I was very pleased with. Being a tool&die maker, I kicked many desighn ideas in my head, freed up in shop and built my first revision. Prepared with 2 wore out sets, along with a set new in the package for good referene; I compressed one sleeve more than the second, falowed with 10 minutes of hand lapping each piston to sleeve set for optimum fit. I fallowed with a few hours of measuring / documenting / comaring to NEW. That evenning I reassembled MT12 engine, and Installed in XXX-NT for breakin and testing. The next morning I richened high end and low end settings and on the box for first start....2 seconds after the fuel completed its travel thru clear line, BAM, started. Ideled for 1 min and cooled, Ideled for 5 min and cooled, Ideled 15 min and cooled, Finally 40 min Idel without one stall. As you could expect some load up after all that ideling, she did stall "once" with first throttle response. Very fast restart(as with the 4 prior) and off the box and on the dirt for 1 tank running with very short bursts of throttle. Please be addvised that the only fourstroken is done on my Harley. Cooled for 15 minutes and for the next 30 minutes I beat the living snot out of that XXX-NT like I was a half a car lenght ahead of Adam Drake....He He Heee! Compression is still excelent! Now, I don't know squat about Airplane engines, but from the local hobby shop I find you guys more layback and conservative than the younger generation of rc car hobbiests. Therfore, I hope to recieve feedback and good constructive critisisium on how this piston/sleeve resizing procedure could be an advantage/or not, with Airplane engines ,ABC construction? This tooling will be user friendly for the advanced hobbiest. Feel free to email me! Stay Cool.....He Hee! Regards, Ray Bagadoughnuts