I'm couple days late in replying to you but reply I must. You are right about ABC (non ringed engines) requiring to be run at proper temp to properly break them in. However, the best way to do so is as I had stated. Run rich to lean to rich to lean do not use throttle at this time run wide open. Alternating the mixture setting allows engine to reach desireablle temperature but then to cool some. If I'm wrong on this guess just been lucky to still have all my engines(about 30) still running great from 50 yrs ago to present. By the way I have run diesels, gas, ( even those that were spark ignition with coils condesers etc.). I had suggested it be started ( blueberry cycle rich)) only for a starting point for a new person. I come here to beginners forum to be helpful if possible and I even learn something from time to time but do not like being told by someone that thinks he knows it all. That I'm wrong. If you had read and digested my entire post you could not find fault