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page 12
May 01/2007
Effectivity 912/914 Series
Edition 1 / Rev. 0
d02621
BRP-Rotax
Maintenance Manual
1)
912 A, F, UL
2)
912 S, ULS, ULSFR
3)
914 F, UL
DESIGN: 4-cylinder horizontally opposed 4-stroke-engine
BORE: 79.5 mm (3.13 in.)
1) 3)
84 mm (3.31 in.)
2)
STROKE: 61.0mm (2.40in.)
DISPLACEMENT: 1211.2 cm³
1) 3)
1352 cm³
2)
CYLINDER: Lightweight metal cylinder with Nikasil coated
running surface
PISTON: Lightweight cast metal piston with 3 piston rings
CYLINDER HEAD: 4 individual cylinder heads
COMPRESSION: 9 : 1
1) 3)
10.5 : 1
2)
INTAKE VALVE: 38 mm (1.49 in.), valve seat surface hardened
EXHAUST VALVE: 32 mm (1.26 in.) NIMONIC, armor welding at
valve seat
VALVE CLEARANCE: automatic compensation of clearance by hydraulic
valve tappets
VALVE TRAIN: OHV, hydraulic valve tappets, pushrods and rocker
arms
CAMSHAFT: steel, annealed, liquid nitriding
CONTROL TIME:
1) 3)
Io. 0° T.D.C. Oo. 48°before UT
(at 1 mm valve stroke): Ic. 48° after UT Oc. 0° T.D.C.
2)
Io. 2° before T.D.C. Oo. 48°before UT
Ic. 48° after UT Oc. 2° after T.D.C.
CRANKSHAFT: supported in 5 plain bearings, case hardened
COOLING: liquid cooled cylinder heads, ram air cooled cylinders
LUBRICATION: 1) Main oil pump circuit:
Dry sump forced lubrication system, trochoid pump
driven by the camshaft, oil return by the blow-by
gases
2) Suction pump circuit:
3)
Extra trochoid pump driven by the camshaft returns
oil from the lower oil sump of the turbocharger to
the oil tank
OIL DELIVERY RATE: 1) Main oil pump:
approx. 16 l/min. at 5500 rpm
2) Suction pump circuit:
3)
approx. 4 l/min. at 5500 rpm
3.4) Engine / Components
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