Just putting in the OS 18CV-RX onto my HPI MT2 now, and am having a problem with the pilot nut. After the washer/collet/flywheel is in place, I try to put the nut on, but I can't tighten it w/o the motor just turning over. In my haste, I didn't compare the shafts for the 2 engines. The old motor is the HPI T-15, the new is a .18CV-RX w/11J carb. Is there a way to 'lock' the motor up so I can get the nut tight? If anyone done this swap, please let me know what to do. Thanks.