Novarossi T21BF 3 Port.
This engine has surprised many racers, running head and head with engines that cost twice as much. This engine has a strong bottom end, and a good top end as well. It produces 2.0 horsepower, and has a range of 6,000 - 32,800 RPM.
This engine runs well with an 086 pipe, or the Mugen 1005. Recommended plugs are Novarossi #6 or O'Donnell 99. Use 30% nitro fuel.
See below for the nitro gurus site