Yamaha YDS7

Make Model	Yamaha YDS-3C
Year	1966-67
Engine	Two stroke, piston-port, parallel twin, Crankshaft supported in four roller bearings; needle-roller small-end and big-end bearings. Light-alloy cylinder head;
Capacity	247 cc / 15.0 cu-in
Bore x Stroke	56 x 50 mm
Compression Ratio	7.5;1
Cooling System	Air-cooled
Induction	2x Mikunis VM24SC with air filter. Direct-operating, coupled air slides.
Ignition	Generator
Starting	Kick
Electrical Equipment:	Mitsubishi 65-watt dc generator charging six-volt battery through automatic voltage regulator. Coil ignition. 6in-diameter headlamp with pre-focus light unit; 35/35-watt main bulb.
Max Power	24 hp @ 7500 rpm
Max Torque	18.1 ft-lb 4.2 kgf-m @ 7500 rpm
Clutch	Wet, multi-plate clutch mounted on left side of crankshaft
Transmission	5 Speed Helical-gear primary drive. Rear chain % x %in with top guard. Engine rpm at 30 mph in top gear, approximately 2,500.
Final Drive	Chain
Gear Ratio	1st 2.545 2nd 1.533 3rd 1.167 4th 0.950 5th .0773
Front Suspension	Telescopic forks with hydraulic damping.
Rear Suspension	Dual shocks swinging arm, Pivoted rear fork controlled by spring-and-hydraulic units with three-position adjustment for load.
Front Brakes	Drum
Rear Brakes	Drum
Front Tyre	3.00 -18
Rear Tyre	3.25 -18
Dimensions	Length 2006 mm / 79 in Width 792.5 mm / 31.2 in Height 1066.8 mm / 42 in
Wheelbase	1470.5 mm / 51.9 in
Wet Weight	145 kg / 320 lbs
Fuel Capacity	11.4 Litres / 3.0 gal