21 TECHNICAL DATA 111
21.1 Engine
21.1.1 All 125 models
Design 1-cylinder 2-stroke engine, water-cooled, with reed intake and
exhaust control
Displacement 124.8 cm³ (7.616 cu in)
Stroke 54.5 mm (2.146 in)
Bore 54 mm (2.13 in)
Crankshaft bearing 1 grooved ball bearing/1 roller bearing
Conrod bearing Needle bearing
Piston pin bearing Needle bearing
Pistons Cast aluminum
Piston rings 2 half keystone rings
X (upper edge of piston to upper edge of cylinder) 0… 0.10 mm (0… 0.0039 in)
Z (height of control flap) 36.5 mm (1.437 in)
Primary transmission 23:73
Clutch Multidisc clutch in oil bath/hydraulically activated
Gearbox 6-gear, claw shifted
Transmission ratio
First gear 14:32
Second gear 15:30
Third gear 17:28
Fourth gear 20:28
Fifth gear 19:23
Sixth gear 22:24
Ignition Contactless controlled fully electronic ignition with digital igni-
tion adjustment, type Kokusan
Spark plug NGK BR9 ECMVX
Spark plug electrode gap 0.60 mm (0.0236 in)
Starting aid Kick starter
21.1.2 All 150 models
Design 1-cylinder 2-stroke engine, water-cooled, with reed intake and
exhaust control
Displacement 144 cm³ (8.79 cu in)
Stroke 54.5 mm (2.146 in)
Bore 58 mm (2.28 in)
Crankshaft bearing 1 grooved ball bearing/1 roller bearing
Conrod bearing Needle bearing
Piston pin bearing Needle bearing
Pistons Forged aluminum
Piston rings 1 rectangular ring, 1 half keystone ring
X (upper edge of piston to upper edge of cylinder) 0… 0.10 mm (0… 0.0039 in)
Z (height of control flap) 36.5 mm (1.437 in)
Primary transmission 23:73
Clutch Multidisc clutch in oil bath/hydraulically activated
Gearbox 6-gear, claw shifted
Transmission ratio
First gear 14:32
Second gear 15:30
Third gear 17:28
Fourth gear 20:28
Fifth gear 19:23