Casing unit: connecting rods

9.3 -

1	Special screw

2	Complete connecting rod

Bearing

4	Threaded dowel

Bushes

Key

7	Crankshaft

8	Threaded dowel

Shim

Parts catalogue


1100	Crankshaft
1100S	Crankshaft

Caution

Bold reference numbers in this section identify parts shown in this exploded view diagram. These parts do not appear in the figures near the text.

Removing the connecting rods


Operations	Reference - See Section
Remove the engine from the frame	N 1, Removing the engine
Remove the lubrication system	N 2.1, Removing the oil pump
Remove the complete head unit with timing system	N 4.2, Removing the timing side covers
Remove the complete cylinder/piston unit	N 5, Removing cylinder / piston assy
Remove the generator-side cover and the complete generator	N 8, Removing the generator cover
Remove engine starting assembly	P 3, Electric starting
Remove the complete clutch unit	N 6.1, Disassembling the clutch
Remove the clutch-side cover	N 6.2, Removing the clutch cover
Open the casings	N 9.2, Opening the casings

The crankshaft now features more centralized weights and lubrication hole in different positions, thus ensuring a stiffer and more reliable behaviour, subject to less vibrations.

Open the casings and slide out the crankshaft (7) complete with the connecting rods (2).

Disassembling the connecting rods

To disassemble the connecting rods, unscrew the bolts (1) and separate the connecting rods from the crankshaft.

Caution

Do not confuse the connecting rods at reassembly. Fit them in the original mounting position.

Overhauling the connecting rods

Run the following dimensional checks on the connecting rods:

-	Connecting rod to gudgeon pin assembly clearance.

Change a connecting rod when badly worn (Sect. C 1.1, Cylinder / piston).

Connecting rod small end bush must be in good condition and firmly set in its seat.

Measure parallelism error 100 mm away from the longitudinal axis of the connecting rod:

H less h must be lower than 0.02 mm. If not so, change the connecting rod.

Two different types of con-rods are now available, A and B, depending on big end diameter (Sect. C 1.1, Cylinder / piston) as punched on con-rod bearing cover.

Use crankshafts and connecting rods from the same class.

Changing the connecting rod small end bush

Pull out the worn bush with a suitable drift and press.

Drill the new bush at the same positions of the oil holes of con-rod small end.

Bore out bush until obtaining a bore diameter (D) of 20.035-20.045 mm.

Changing the connecting rod big end bearings

Change the bearings (3) every time the engine is overhauled.

Spare bearings are supplied ready for installation. They must not be reworked with scrapers or emery cloth.

Two different size classes are available, each marked with a different colour: YELLOW or BLUE.

They consist of an outer steel support and an inner lead-base layer obtained through electroplating.

The table below shows bearing color to be selected according to crankshaft and con-rod classes.


Crankshaft class	Con-rod class	Bearings colour
A	A	Blue + Yellow
B	A	Yellow + Yellow
A	B	Blue + Blue
B	B	Blue + Yellow

Overhauling the crankshaft

The main bearings journals and the crank pins must not be grooved or scored.

Threads, keyways and slots must be in good condition.

Check for fretting or burrs in the fillet between crank pin and shoulder.

Fillet radius: 2 mm.

Use a micrometer to measure oval and taper of the crank pin. Measure oval and taper in several different directions.

Use a dial gauge to measure the alignment of main bearing journals with the crankshaft placed between two centers.

Clean inner channel of the crankshaft at each overhauling.

Two different crankshafts are now available, A and B, depending on crank pin size as punched on web side on sprocket side.

Undo all crankshaft plugs (4) and (8). If they are hard to remove, heat plugs to remove the threadlocker used at assembly.

Clean all lubrication ducts with suitably sized metal brushes and blow with compressed air to remove any deposits preventing proper oil circulation.

Apply DUCATI liquid gasket to the threads of the plugs (4) and (8) and then refit them.

Tighten all plugs to the specified torque (Sect. C 3, Engine torque settings).

Big end bearings-crank pin clearance

To check clearance between big end bearings and crank pin, use a GREEN “Plastigage PG-1” bar (A) on the crank pin. Fit the connecting rod with the original bearings. Tighten the bolts to 50 Nm.

Remove the connecting rod and check thickness of the bar looking at the reference line (B).

Replace the bearings or the crankshaft if the thickness measured (the clearance) is not within the specified limits (Section C 1.1, Cylinder / piston).

Reassembling the connecting rods

Before reassembly, check that main bearing journals and crank pins are free from burrs and fretting: use fine emery cloth and oil, if necessary.

Check that splines are in perfect condition and without signs of shrinkage.

Make sure each connecting rod (2) has its locating pins (D) in place between cap and shaft.

Wash pins and dry them with compressed air.

Clean and lubricate con-rod bearings (3) and crank pin with engine oil. Refit the con-rods in their original mounting position.

Warning

Corrosion and irritant hazard. The grease is an irritant. Avoid contact with skin and wear protective gloves.

Caution

Failure to grease the con-rod bolts will lead to incorrect clearance and breakage.

Fit the spacer part no. 88713.1309 between the con-rods and take up the residual axial play with the fork feeler gauge part no. 88765.1000 available in 0.1 - 0.2 - 0.3 mm.

Tighten the screws (1) as described:

Lubricate with the recommended grease;

first tighten to 20±1Nm;

secondly tighten to 32±1Nm;

Tighten to 67 Nm.

Refitting the connecting rod unit

Install the complete connecting rod units (7) and (2) inside casing, proceed to shimming and close casings as described in Sect. N 9.2, Casing unit: crankcases.

Caution

Make sure that the connecting rods (2) are correctly positioned in the cylinders. Incorrect positioning will inevitably lead to reopening of the casing.


Operations	Reference - See Section
Refit the clutch-side cover	N 6.2, Refitting the clutch cover
Refit the complete clutch unit	N 6.1, Reassembling the clutch
Refit engine starting assembly	P 3, Electric starting
Refit the generator-side cover and the complete generator	N 8, Flywheel - generator
Refit the complete cylinder / piston assembly	N 5, Refitting cylinder / piston assy
Refit complete head assembly and timing system parts	N 4.2, Reassembling timing belt rollers on layshaft
Refit the lubrication system	N 2.1, Refitting the oil pump
Refit engine to frame	N 1, Reassembling the engine