RE: RC engine quality control? Does exist?
You wanna try a real junker, i got a Leo 46 with maybe 20 flights on it. Had to replace the carb from new. And the crank pin where the connecting rod installs os worn out. It did not get lean runs and always had 20% oil. I also have an old Magnum 40 pro that was a dissapointment from day one. No power and poor reliability. It had an interface with Terra firma. I am not going to fix it.
You just seem to have some bad luck. I have had a bunch of Saito's without problems. I also have a Super Tiger 45 and an MVVS 40 that are just fantastic. Good luck getting your problems squared away.
Mark Shuman