Scott..I will watch this post also.I do not know of any stand alone relay that senses engine stall.If such a beast exists..then I want one also.Maybe a manifold vacuum referanced diaphram/switch could interrupt the ground side of the relay coil?The downside would have no carb prime during cranking perhaps..but the fuel bowls should be full and allow start up anyhow.It is a great question that airs on the side of safety in a rollover especially.Hopefully someone chimes in.:thumbsup: