Hi everyone, I have a problem with my husaberg, the point is that there is a problem with the 4th gear as I go, sometimes it jumps in this gear and I wonder if it's a problem with the clutch or the gearbox? , I will add that when I put the engine together, I did not give the washer that was in the box because I did not know where it was, gentlemen, what do you think is the reason I have a 4-speed gearbox?