I have an 89 201 pro. the valve for the tanks is back by the motor (you know what). the switch on the pannel by your livewell switches is for the gauge. flip it when you switch tanks so you know how much is in the one you are using. port for the port side tank, starboard for the starboard tank. truthfully, I wish that boat had one tank under the seat in the middle of the boat so you would have more storage.