I don't even try to start big glow engines by hand flipping them through the compression stroke anymore. I just prime them a little on the wet side and spin them backwards by grabbing the spinner with my finger tips and let the kickback that results do the engine starting. This doesn't work on gas engines with spark ignition though. I hear that paint rollers make good chicken sticks for big engines and they are soft enough to not damage the prop if there is a big kickback.