I think the confusion exists because there is a button on the GSU called "AIR" which spins the motor using the electric start motor. and does nothing else. As far as I know there is no facility on the ram 500 for starting it using compressed air. BV recommends that the engine is first spun up to 1000 using the "Air" button and then a full start is initiated. I believe this is to ensure that any voltage drop caused by the initial start current is minimised so that required voltage can go to the plug to optimise propanne igmition. Havng said that my RAM 500 was starting beautifully yesterday just by pushing the start button or using the throttle stick. My RAM 500 is number 22 but has the latest ECU. And according to Carlos make sure the EGT probe is only about 1/16th inch inside the tailpipe. Yes, it is a gem of a motor and sounds delightful when spoolong up or slowing down in the air .