RE: SK 90-----WOW
Welcome Gonzalez.It is the problem of LSN while testing in Kangke(I dont think they make tests in factory in China) adjusting to good run not for break in so it is not allowing to richen for 4 stroking.I dont use any SK 90 and Ed is doing great job on those engines so I cant say more about props but seemed your revs are low.Recommend you to tighten the head screws and backplate again(with care please).