Originally Posted by
hoppyasl
There are various reason a M14P/PF could fire when pulling through...... magnetos left on, short in the magneto lead or hot spot on the piston head amongst the main ones.
Normally a shorted p lead will inhibit a magneto. The "short" provides a ground path that is in parallel with the mag switch. It requires an "open circuit" p lead to enable a magneto when the mag switch is in the off position.
Is there something unusual about this engines magneto configuration?