Z300 HPDI shift switch

[Regulator 23]

My mechanic told me that the "shift switch" on my 300 HPDI that shifts the engine from 4 cylinders at idle to 6 cylinders while its running faster was faulty. I feel a small bump every few minutes while running, but nothing major and he thinks that switch is faulty. Makes sense. I've tried to do a little research to learn more about it, but can't seem to find much. Is the switch maybe called something different? Thanks.

[boats.net]

There are two switch's on shifter, one is the shift switch and the other is the neutral overrev switch Yamaha call's both of them switch assy.

[Regulator 23]

Thanks for the info!