Originally Posted by silvaire
I think silicone wire insulation of some size would probably work well, but I haven't tried anything yet.
I've been using silicone wire insulation almost exclusively on smaller planes. It's very flexible, completely fuel proof and comes in a variety of colors and sizes. The pic with the clunk is a 35mm film can, so it gives you an idea of how flexible the insulation actually is. For the Dragonfly, 14 or 16 gauge wire might work --- the wire size in the pic is 14 AWG. With the smaller engines, fuel flow is so low that tubing ID can be quite small.