Also known as the "Poor man's Tee Dee" these were similar to the Tee Dee in appearance but had cheaper parts on them, making them cheaper to buy. The cylinder was a non-tapered twin bypass with no boost ports (like the one used on the Black Widow), the crankshaft was drilled out rather than milled like the Tee Dee, and the carb body was a one-piece unit with a conventional needle valve and spray bar. These engines were marketed as a Sport / Stunt engine as they were much tamer and much less cantankerous than the Tee Dee. These are a great reliable easy to use little engine even today. They can be purchased for under $20US in 2008. R/C versions of this engine were also produced with exhaust throttle. i.e. 1968 Cat#240-1 and the 1988 Cat#2501 with muffler/throttle.