I was a little off on the serial # of the engine that failed. It was F00669, and was purchased off a seller on RCU as mounted, never run. I also have one that I bought off Tower last year, serial # F04887. I wonder if the crankpin issue has even been addressed at DLE?

For giggles, I also pulled out the instructions that came with the engine. I can't find anything in there mentioning max RPM, only that it makes peak HP at 9K. I also note that one of the recommended props is a 15X8, which would result in excess of 9K easily?

Better late then never to read the dang directions, I see they're dreaming about using 93 octane go juice. I use whatever's on sale and didn't see any evidence of detonation, so I doubt that's a big deal.