Just thought I would mention that my early Magnum .28 which was made in Taiwan (Thunder Tiger) had a tight crank seal. I had to polish the crank to make it looser. Then it ran gangbusters.. It was surging and the case was hot, really bad runner before. I have a lot of old T Tigers with tight or sloppy crank fits that give bad runs. We run 8-6s on our .25 size schnuerle motors and they seem quite happy.in the 16,000+ rpm range. Maybe the motor was for sale because of the tight crank fit giving problems, and hopefully the lack of compression was just from that cause. It caused me a lot of grief before I fingered that one out. The bottom of the case was very hot after only running a short time.