If this is a SIMJET 1200, the idle speed is 50,000 > 52,000 rpm. For a 2300 or 3000 the idle is 30,000 > 31,000.

When you shut down the turnbine, you need to do so from the TX using the Trhottle trim lever. If you do so by turning off the power to the ECU, the cool down cycle will be terminated and the cool down will not take place. In this event, turn Rx power off, then back on and advance the Throttle stick to high and this will re-initiate the cooldown.

As for the starter engagment, you may need to replace the O-ring or check to see that the Brass bendix assy. is functioning and extending properly and may need just a drop of oil in the pin slot. You can "re-use" this O-ring by removing it with a straight pin and turning it over and re-installing.

IF you have the older style SIMJET where the motor has to manualy clearanced to the compressor nut, that is easily done by removing the starter nose cone, sliding the starter motor forward unitl it just touches the compressor nut. Place a pencil mark onto the electric motor housing at the rear of the aluminum starter housing. Using this line, back the starter motor away from the compressor nut 3/32" and carefully re-install the nose cone which will lock the starter motor into the correct position. All should work properly if the O-ring is in satisfactory condition.