Bold reference numbers in this section identify parts not shown in the figures alongside the text, but which can be found in the exploded view diagram.

In the event of excessive wear (Sect. 3 - 1.1Crankshaft), replace the connecting rod.

Check for parallelism error measured at 100 mm from the connecting rod longitudinal axis:

the value must be H-h less than 0.02 mm; otherwise, renew the connecting rod.

The connecting rod is supplied in two size classes A and B relative to the big end diameter (Sect. 3 - 1.1Crankshaft) as punch marked on the side of the cap.

Now ream out the bushing until the inside diameter (D) is 20.035 to 20.045 mm.

Fillet radius: 2 mm.

The prescribed values are given in Sect. 3 - 1.1, Crankshaft.

The crankshaft is supplied in two size classes (connecting rod pin) A and B, as punch marked on the side of the crank web on the pinion side.

Loosen all crankshaft plugs (4) and (7); heating the crankshaft, if necessary, to remove the threadlocker applied at the time of assembly.

Clean all the oilways using suitable diameter metal brushes and then blow with compressed air to remove any residues that have accumulated and are restricting the oil flow.

Apply prescribed threadlocker to the plugs thread (4) and (7) and then refit them.

Tighten all plugs to a torque of 13 Nm (Min. 11 Nm - Max. 15 Nm) (Sect. 3 - 3, Engine torque settings).

To check the assembly clearance between the bearing shells and crankshaft journals you will lay a strip (A) of GREEN “Plastigage PG-1” on the journal. Fit the connecting rod with the original bearings and tighten the screws to a torque of 50 Nm.

If the width measured corresponding to the existing clearance is not within the prescribed limit (Sect. 3 - 1.1, Crankshaft), either the bearings or the crankshaft must be replaced.

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.

Take the bearings (3) necessary to shaft/connecting rod coupling, following the indications provided (Sect. 3 - 1.1, Cylinder/Pis­ton).

Insert the bearings in the connecting rod seats matching the tooth (M) of the bearings with the corresponding marks (N) on the connecting rod cap (F) and on the connecting rod small end (G). It is essential that the tooth (M) adheres perfectly with its own mark (N).

In the case of BLUE and YELLOW bearing coupling, fit the YELLOW on the connecting rod and the BLUE on the connecting rod cap.

Join the connecting rod cap (F) with the corresponding connecting rod small end (G), checking that the progressive number stamped on the two pieces is the same, as shown in the figure.

Fill the recommended grease into the two ends of the hole to lubricate threads and underside of the new screws (1) and the thread of the shaft.

The big-end cap screws may only be used for one tightening.

Fit the spacer (H) of the tool 88713.2878 between the connecting rods and take up residual axial clearance with the fork feeler gauge (I) of the tool 88713.2878 which is available in the following thicknesses:

0.1 mm - 0.2 mm - 0.3 mm.

Tighten the screws (1) with a torque wrench and angle reading (degree wheel) in accordance with the procedure described below (observe the same tightening sequence at each step as that of the previous step):

If the final angle is less than 55° or greater than 75°, repeat the procedure using two new screws.

Install the connecting rod assembly (6) and (2) in the crankcase, carry out the shimming and crankcase half reassembly procedure as described in Sect. 9 - 9.2Reassembly of the crankcase halves.

Make sure that the connecting rods (2) are correctly positioned in the cylinders. Incorrect positioning of the connecting rods at this stage will inevitably lead to the need to re-open the crankcase half.