The first thing to note is that the indicators are broken. Did you notice the indicators on the device in the corridor next to the Garage? They can be used to check the gas ratio. If you check them before making any adjustments, the gas ratio will be 0:100.
The paper on the wall next to the device in the corridor illustrates that the dial and small levers must be used to adjust the ratios shown on the indicators.

The dial has settings from 1 to 6 on it. The small levers have numbers below them, and it shouldn't be too difficult to work out that the middle number (scratched out) is 4.
From the formula at the bottom you know A (dial) is multiplied by B (small levers) to set the ratio.
Do you recall seeing something that shows a correct setting for the dial? If you read the paper lying on the floor (through the secret door where Hansen's head is) you would have found the password for Kurt's computer, i.e. 002YZ1. When you now access the computer it will be a password option.

1) Select 'Administrator' and 'Confirm'

2) Select 002YZ1 as the password

3) Scroll down to 'Unformat Disk' and 'Confirm' to see a number of .jpg files on the left

4) Scroll down to 'Back' and 'Confirm'

5) Select 'Administrator' and use left directional arrow to view the .jpg files

6) The second last picture (mv559.jpg) shows the dial set to 3

7) Select 'Log off' to exit from the computer

Experiment with the dial and small levers to learn how the gas ratios are affected. You work out that there's a definite pattern. Multiply the number the dial is set to by the total of the numbers below the levers in the 'up' position to get the left value of the gas ratio. Deduct this same amount from 100 to get the right value of the gas ratio. Initially the gas ratio is 0:100, so the dial and levers must be set to add up to 66. This gives you the ratio Scott Piper told you to use, i.e. 0+66 (66) : 100-66 (34).


Set the dial to 3 (press the first three buttons at the top)
Push the 2nd, 3rd and 5th levers up - this adds up to 22 (2+4+16)

3 X 22 = 66

Note that it's also possible to get a gas ratio of 66:34 if the dial is set to 6. However, it didn't work for me so it seems you must use the solution given above.
After correctly adjusting the gas ratio to 66:34 push the large lever up. You hear the gas hissing and should automatically exit from the red panel.