RE: Evo 61nx vs O.S. 65AX
Parts are about 40% of what OS charges.
The liner has fairly hard chrome that takes a few tanks to start loosening up. OS uses a nickel plate process.
Performance of any Evo glow engine that I've seen beats OS. Be sure to run a hotter plug than the OS 8.
I know these opinions will step on toes, but I'm being honest.