The prop should of course always be treated as 'live' in case an earth lead has failed, but merely touching the thing won't set if running!
The Chipmunk requires to be pulled through 4 compressions before starting, to check for 4 good compressions and no hydraulicing (it's an inverted engine). We just treat it as live in case it starts when doing this. In fact, the attitude to take is to be surprised if, when pulling it through, it doesn't start!
A bit like expecting the engine to fail on take off and being relieved if it doesn't, rather than being completely taken aback if it does!
Last edited by Shaggy Sheep Driver; 19th October 2012 at 18:06.