Des switch

[bigeagle172]

We have two 3oo hp 2005 2 stroke Yamaha Outbbaords. The port engine shuts down to 2 cylinders at 2000rpm. We have changed all the sensors, fuel pressure is good and no faults showing up on the computer. The only thing we can find as wrong is the DES switch display on the computer that we connected says the DES switch is on. In the service manual it says if thiswitch is on 4 cylinders will misfire at 2000rpm. We get that exact responsde at 200rpm. Can anyone tell us how to change this setting:
DES ON to DES OFF. We have had two techs on board and talked to 3 techs and no one has heard or this problem or knows how to correct it.
HELP
bigeagle172

[99yam40]

What does DES stand for?

From what I have read and think I understand, the motor is designed to not fire all of the cylinders if it is in neutral and reved up.
So if this DES switch is the one that tells it it is in gear or neutral then that could be your problem.
See if it is out of adjustment or malfunctioning(broke)