Suzuki T305

The T305's engine was a development of the T20, which had been introduced in 1966. The 180° piston ported two stroke twin was of unit construction and had alloy head and alloy barrels with cast iron liners. The T20's bore was increased 6mm to 60 mm (2.4 in) whilst the stroke remained at 54 mm (2.1 in) giving a displacement of 305 cc (18.6 cu in). The engine had the compression ratio reduced to 6.7:1 and heavier flywheels than the T20 to aid low speed tractability. Claimed power output was 37 bhp (28 kW) @ 7,500 rpm, giving the machine a top speed of 95 mph (153 km/h).[1][2]

Fuel was delivered by twin 32 mm Mikuni carburettors. The engine was lubricated by the Suzuki Posi Force system which injected oil to the main bearings and conrod journals.[1][2]

Primary drive was by helical gears to a multi-plate wet clutch, which had larger plates than the T20 to improve longevity. The six speed gearbox had larger gears than the T20 to improve reliability. Chain drive took power to the rear wheel.[1][2]

The duplex cradle frame of the T20 was retained. Rear suspension was by swinging arm with twin shock absorbers. At the front telescopic forks were used. Brakes were drums front and rear, the front being an effective 2ls item.[1][2]