Traxxas's TRX 2.5 engine with multi-shaft without pull-start, slide carburetor provides less restrictive, straight through airflow for more power and better throttle response. Exhaust header features an extra-tough, finned mounting base that dissipates heat and is sealed with a reliable O-ring gasket. Molded head protector prevents damage to the head and secures the glow plug wire. Innovative cast cylinder head is engineered for the most heat reduction possible. Tubular header features smooth, rounded bends to eliminate exhaust flow restriction and turbulence. Ultra-low restriction air filter provides superior air flow and filtration for more power and a long engine life. Offset wrist pin further reduces piston slide loading for more even cylinder wear, and longer engine life.