The OX66 is supposed to be pretty solid. So was the the 2.6L 200 HPDI that I had however I must’ve gotten the 1 in 1000 that was a piece of shit, $6k, 3 dealerships, and 6 months later it still wouldn't run right. 6 months out of warranty and Yamaha nor anyone else wanted anything to do with it. Unfortunately it was my first, only , and last Grey motor I’ll have for some time. I’ll take my noisy big block Opti every day of the week and twice on Sunday!
FYI, yes they are both high pressure direct injection 2-stroke engines however they achieve it very very differently. The HPDI fuel system is more complex than the space shuttle using several fuel pumps, and 9 or ten filters including the cups at each injector. To say they can be sensitive with fuel is an understatement. The Opti uses an air compressor to to pressureize and atomize the fuel through a separate air injector. And as someone else mentioned, the HPDI gets a “mystery” filter inside the non-serviceable high pressure pump that’s the size of an eraser, brilliant! FYI, that pump is a couple $k.Am I sour, yep, still stings... is there someone with a bad experience with an Opti or Verado; probably and probably even on this forum. Bottem line, do your do diligence, check it over inside and out, water test it, and cross your fingers your not buying somebody’s problem. This is the joy of buying used.
good luck, lol