I am new to the world of RC and just bought my first plane but I am a electronic tech. the capacitor is a starter capacitor which does help the motor start turning... If you can not find any information on the Capacitor, take it to you local TV shop and they should have a capatiance meter and be able to tell you what it is and maybe even have one. It should not be to critical as long as you can get close to the value. the voltage i wouldn't worry about as long as it is a little over the battery voltage. It can have some filtering value also.....