I have been in the machine industry fore many years and have manufactured a few gears in my time. There is an angle machined on each tooth . Doesn't matter how many teeth each geer has. It has to mesh with another geer. Geers can be maid to be noisy or quiet, depends on the lead angle of each tooth. Example If you have been close to a hot rod chevy wile its running you will hear a high pitch wine in some of them, this do to changing the timing chain to a gear drive. these gears can be bought two ways noisy or quiet. the difference is the lead angle of the tooth . When Yahama offers us venture owners different letter clutch baskets (H) (I) (J) whatever, Its a shot in the dark hoping it fixs the problem,and fore a short time it may. The problem i think, is that the mating geer is not changed and Yahama is hopping one will wear in to the other, somtimes it does other times the wine comes back. Yahama does not want to pay to split the geer case and replace the mating geer. Just my thoughts.