MY TECUMSEH 10 HP ON A PRO AIR 30 GALLON AIR COMPRESSOR BUILDS UP AIR THEN IT SHUTS OFF INSTEAD OF GOING TO LOW IDLE

The pilot valve or control valve when it unloads sends a air signal to close the motor throttle down to idle and depending on what form of control it uses for the compressor it will either use head unloaders to hold open the inlet valves or a unloader that dumps the compressor output to atmosphere, this one uses a silencer mounted near the pilot valve. if it uses this type remove the silencer and retest the operation. either you have a motor that is out of adjustment or the compressor is not unloading!