How do I change the mix ratio on the proportioner?

To change the mix ratio, one or both high-pressure displacement pumps need to be replaced, the air motor needs to be re-positioned, and the over pressure relief valves may need to be changed. Check the XP Pump Assemblies table for correct pump sizes, remove and replace the pump, adjust the motor position, install the correct over pressure relief valves for the new system type, and change the Air Pressure Relief Valve (MG) as required for the new ratio. (Page 42)