I just got a new engine for my buggy. It came with a yellow and an orange reducer for the carb. Does anyone know what these are for?

..to reduce fuel consumption. If you're not racing, I would forget about them..

Found this description at a Tower Hobbies listing: "Mounts into carburetor to reduce the amount of air flow which assists in increasing the amount of torque produced"

They are called carb restrictors. They do a few things, the most important is reduce the amount of power produced by the engine, Which they do by restricting airflow, less air means less fuel, which means less power. This is especially useful in off-road, is these engine produce more power than we can use at times. As a by-product they do increase fuel economy, and usually make the engine easier to tune as well...

Alright, that makes sense. Thanks guys.