Ducati Diavel
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Ducati Diavel Service Manual: Cylinder compression test

Note

The on-screen icons used during this procedure are explained in a table at the end of this section.

Engine performance is directly correlated to the pressure that can be measured in the combustion chambers of the two cylinders. Pressure which is too high/low or an excessive difference between the two cylinders will cause a drop in engine performance and can cause engine breakdowns.

Cylinder compression test


To reach the vertical head spark plug lift the tank up as specified under the section 8 - 2 "removal of the fuel tank" and fit a drift under it.

Run the engine so that it warms up to the point that the fan is tripped at least once.

Open the throttles completely.

Remove the ht leads (1), unscrewing the nuts (2) of both spark plugs.

Remove the spark plug from the cylinder to be tested.

Cylinder compression test


Cylinder compression test


Connect the ht lead to earth to prevent sparking.

Screw the cylinder compression cable part no.552.1.038.1A into the spark plug compartment.

Connect the pressure sensor part no. 552.1.039.1A to the cable with part no. 552.1.038.1A..

Turn on the dds diagnosis instrument (3) referring to the paragraph "connection to the motorcycle".

Connect the power and diagnosis cable (measurement module) (4) part no. 97900.0222 To the measurement module connector (b) of the dds (3).

Cylinder compression test


Connect the pressure sensor part no. 552.1.039.1A to the outlet (a) or (c) of cable (4) part no. 97900.0222.

Note

Measure the compression on one cylinder at a time.

Cylinder compression test


On the dds diagnosis instrument (3), select the "measurement module" function by pressing the corresponding icon; then press the "cylinder compression" icon (d) followed by the "start" icon (e).

Cylinder compression test


Cylinder compression test


The socket to which the cable (measurement module) (4) is to be connected is indicated on the screen with a capital letter: a, b or c.

Turn over the engine with the starter motor until the pressure stops rising.

Check the pressure in each cylinder:

Cylinder compression test


An excessively high pressure value can be caused by:

An excessively low pressure value can be caused by:

Refit the spark plugs and position the coil-spark plugs wires (1) in the corresponding compartments and tighten the nuts (2) to a torque of 10 nm (min. 9 Nm max. 11 Nm) (sect. 3 - 3, Frame torque settings).

Cylinder compression test


Cylinder compression test


Refit the tank as indicated in section 8 - 2 "refitting the fuel tank".

Cylinder compression test


Check the engine oil pressure
Note The on-screen icons used during this procedure are explained in a table at the end of this section. To measure the pressure of the lubrication circuit, use the engine oil pressure test po ...

Fuel pressure test
Note The on-screen icons used during this procedure are explained in a table at the end of this section. Undo the screws (2) and remove the flange cover (1). Remove one of the two pipes o ...

Other materials:

Reassembly of the connecting rods
Before starting, check that the crankshaft main bearing journals and big-end journals are free of burrs or evident signs of machining: if necessary, clean the surfaces with very fine emery cloth and oil. Check that the grooves are in perfect condition with no signs of forcing. Clean the cra ...

Refitting the airbox and throttle body
Position the filter box (1). Operate on the vehicle lh side, connect connector (f) of the tps/div motor. Operating on the right side of the vehicle, connect connector (e) from the aps sensor. Check for the vibration dampers (20) on the map sensor supporting bracket (19). Insert t ...

Overhaul of the crankcase halves
Carefully examine the engine crankcase halves. Check that the surfaces of the crankcase halves are perfectly flat using a reference surface. Check that the bearings (1) and (18), and the bushings (2) and (17) are in optimum conditions. Note that the main bearings must always be changed in p ...

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