Cox reed valve performance
Here's an engine mount/reed/venturi adaptor one I drew up a few years ago and friend Roger Armstrong machined for me. It uses a stock mylar reed, a bushed down TD venturi/needle assy. and an exhaust throttle sleeve. I called it the "Poor Man's Space Hopper."
It's neat looking but is heavy and doesn't run as well as a mod'ed TD plus has the rich low/mid range problems that I've always had trouble with on reed engines. You'd think a reed would have better fuel draw and metering down low but I've never been able to get them to run as consistently as a TD. The crankcase wear problem is always there as well....TD's do much better over the long term