Had it flying with the carbie on the inside of the fire wall, but a landing in a creek popped the fire wall out so I installed a new fire wall 28mm back and reinforced the sides with some blocks. The perimiter of the original fire was glued back in, this gave me something to fix the cowl to on the original bolts, and reinforced the front. It also made easy access to the glow plug, as this was not easy to get too before. Will throw some pics when I get a change.