Application: Saito 120, inverted, VF Edge 540. In the inverted position the glow plug points down and back, making it difficult to get to when the motor is concealed in the cowl and dangerous to unplug when the motor is running. I have since been able to adjust the motor for more consistant starts, although I am still running it rich at this time (4th tank, 14oz). The use of an onboard glow is an effort to maximize safety and ease of starting, as well as, increase engine reliability in flight.