YAMAHADT-3 250 1974 - 1975

　　The DT's engine was your basic 250cc air-cooled two-stroke single that was dirt reliable plus dirt cheap to operate and maintain. Fed by a 26mm Mikuni carburetor and with 6.8:1 compression, the 246cc (15 seven ports on its "Torque Induction" two-stroke engines). Along with the standard intake, exhaust and transfer ports, Yamaha used an additional two transfer ports along with holes in the piston skirt. These ho would normally be covered by the skirt. This small detail resulted in a slight increase in power, and better throttle response than Yamaha's pre 1972 engines.