There are a lot of advantages to going with gas, like cleaner operation and cheaper fuel. But Saito™ 4-stroke gas engines give modelers more, namely some of the most impressive power-to-weight ratios in their class. The FG-21 engine is no exception. Based on the groundbreaking Saito FG-20 engine, it packs 21cc of power into a 17cc case. Accompanying the extra displacement is the latest carb technology, updated exhaust valve seats and, of course, the sweet 4-stroke sound Saito engines are famous for.