It does not matter what position the dizzy is in, if everything working ok you will get a spark just at the wrong time that's all.
Have you inadvertantly disloged a connector ?, do you have a dodgy CPS connector as these do play up ?, have you checked the phase gap ?
Take king lead out of cap and rest near body work then turn over and see if it sparks, if like me you may have forgotten to put the rotor arm back in.
tabetha