RARE VINTAGE McCOY "SPORTSMAN" .29 C/L - F/F REAR-ROTOR RACING SPEED MODEL AIRPLANE ENGINE, CIRCA 1949, MADE IN USA BY DURO-MATIC PRODUCTS! Displacement is .296ci Taken from an ad on e bay.

It's a fixed venturi cast into the case, there is no carb upgrade for it. I never heard anything good about a McCoy in latter years when they failed to stay in business. You could easily pick up a small .25 schnuerle port airplane engine for RC that will fit the application out of the box.