Checking the total advance with a stroboscope
Carry out the following:
1. Mountthe advance checking indicator 88713.0109 on
the driving shaft centre line, flywheel side, after removing
the plug 0400.49.090.
2. Connect the stroboscope light cable to the spark plug
3. Start the engine and run at about 2,500-3,000 r.p.m.
then shine the stroboscope on the reference mark for the
cylinder being tested, placed on the clutch side cover.
4. The phasing indicator must align with the reference
mark, and the ignition coil should be turned clockwise to
advance and anti clockwise to retard until the two
Four stroke twin cylinder, 900 longitudinal "L" configuration, supported in a cradle frame.
Bore: 86mm (3.387")
Stroke: 74.4mm (2.93")
Total Capacity: 86.9cc. (52.700 cu. in.) .
Compression ratio: 9:1 .
The engine is basically similar in construction to the Ducati 750, with the exception of the
electronic ignition system.
The electronic ignition system consists of the following components:
a) Generator - with the magnetic flywheel attached to the axle on the left hand side. Access
to the generator is via the left hand cover and clutch.
To time the ignition: 1. Fit the protractor wheel to the engine axle.
. 2. Bring the vertical cylinder
to T.D.C. and setthe protractor
wheel at "0"
3. Rotate the engine anti-clockwise and position it at 38° in advance.
4. Turn the magnetic flywheel using a pin inserted into the hole, rotating
it until the pin slips into the corresponding hole on the stator plate.
5. Tighten the three screws which fasten the stator plate.
b) Transducers - mounted under the fuel tank.
c) Spark plugs - Champion L 88 type.
With a valve/rocker clearance of 0.05-0.08mm (0.002"-0.0031"), inlet and 0.01-0.12mm
(0.0039" -0.0047"), exhaust, the valve timing is as follows: Inlet opens at 48° before T.D.C. and
closes at 830 after B.O.C. Exhaust cpens at 830 before B.O.C. and closes at 480 after B.D.C.
Clearances should be set with the engine cold and after the timing has been adjusted.
Petrol is gravity fed to two Dellorto carburettors, type PH F 32 AD for the front cylinder and type
PHF 32 AS for the rear. The main jet is set at 122, and the idle jet at 60. The taper needle equals
K/6 at the second notch and the diffuser measures 32 mm.