Reassembly of the connecting rods
Before starting, check that the crankshaft main bearing 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.
Thoroughly clean the crank pin (7) on the crankshaft (1) and lubricate with ROTHEN EXTRA additive.
Take the bearings (4) necessary to shaft/connecting rod coupling, following the provided indications.
 
Crankshaft class
 
Con-rod class
 
Bearings colour
 
A
 
A
 
RED - RED
 
B
 
A
 
BLUE – BLUE
Insert the bearings in the connecting rod seats matching the tooth (H) of the bearings with the corresponding marks 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.
Lubricate the bearing (4) fitted on the connecting rod shank with ROTHEN EXTRA additive.
Install connecting rods onto crankshaft.
Join the connecting rod cap (F) with the corresponding connecting rod small end (G), checking that the laser mark (M) stamped on the two pieces is the same, as shown in the figure.
Warning
The grease utilised is irritant in contact with the skin; wear protective gloves.
Important
Lubrication of big-end cap screws is essential to obtain the correct coupling and to prevent breakage of the parts.
The big-end cap screws may only be used for one tightening.
Tighten the screws (3) by hand.
If this proves difficult or if the screws jam, undo them and lubricate them again.
Remove excess grease. Tighten the screw by hand until the head seats against the connecting rod.
Temporarily fit the gudgeon pin (L) to align the connecting rods.
Place spacer (S) of tool 88713.2878 between con-rods and take up residual axial clearance with the fork feeler gauge (T) of tool 88713.2878 which is available in the following thicknesses:
- 0.1 mm - 0.2 mm - 0.3 mm.
Using a torque wrench, as shown in the figure, tighten screws (3) to the following torque values:
-
tighten to 35 Nm;
-
pause for 2 seconds and then back off through 360°;
-
snug to 20 Nm;
-
snug to 35 Nm;
-
tighten to 65° ± 1°;
-
torque check 70÷103 Nm.
Remove feeler gauge and check that the axial clearance between connecting rods and crankshaft is: 0.15÷0.35 mm.