We know all that but with the bore scored they will not fire regardless of the compression. I haven't bothered honing PT's because there is so many thrown out everywhere, just pick up another one off the street. I hone the F/C's because they are getting harder to come across and they are a fantastic motor, I use them on slashers/ sidethrows. Not a kick out of them with my test carby, hone and new rings and they will fire straight up
I found an old case that I could use to rebuild a new motor from. the coil leads on it are only for the carburettor curt out leads. Do some later power torque coil not require an ignition module. it doe snot even have a hole for the rivet nor the third lead on the coil as the old ones have two leads on one connector and one lead on the other connector.
I had one Stihl chainsaw that had 140 psi that would not start to save your life. It turn that it was losing all it compression right top of the stroke due to cylinder damage. The compression gauge was just the build up pressure prior to the dump of pressure.
It had me scratching my head until I took it apart.
Hi AVB, good point, makes sense, I hadn't thought about that, loosing comp right at TDC I just knew they wouldn't start if they have that visible piston damage through the exhaust port. Was worth getting out of bed today to learn that I will take that to my grave.