Suggestions to Preston Briggs
This site was last updated on February 15, 2008.
In the US, recent AMA rules require that planes used in combat have fuel shutoffs (if they fly faster than 75 miles per hour). The shutoff must kill the engine if the lines are cut. These new rules have inspired a rush of innovation as builders sought to develop cheap, reliable, and robust shutoffs.
There's now a forum dedicated to shutoff design.
These pictures were taken by Howard Rush at Riverside. They're a couple of interesting homebrew designs, both relying on line tension to keep the fuel line open.
The picture above is a home-built design by Mel Lyne. Simple enough? Below is a similar approach by Mike Rule.
The picture below shows a particularly engaging combination of a swing-arm shutoff (with the swing arm removed) and a line-pull shutoff.
Notice that neither shutoff is functioning!