These issues described above are very likely down to a mix-up that happened somewhere along the way at the Rok factory involving the power valve spring. Some engine’s spring is to heavily sprung and causes the poor performance.
I had heard about this but became more keenly aware of it after ordering a spare spring, and to my surprise (dismay) it was a very different spring than what it was supposed to replace. The video below has all the details and images you need to see, but I can 100% confirm that this is a real issue, as I now own both the springs you see in that video. Not only does he show the measurements of both springs, but he also dyno tests them both and the heavier one essentially breaks the engine performance-wise. I don’t know how there isn’t more official notice given about this on ROK’s own sites at least, but in any case that’s the deal, and the wrong spring might still get shipped to you if you order a replacement part.
