If new units are used, it is necessary to couple the cylinders and pistons of the same selection (see paragraph "overhaul Of the cylinder barrel/piston components" of this section).
If the pistons have been separated from their cylinders, before reassembling these components, position the piston ring gaps at 120 from one another (the markings must always face the piston crown).
Note
For better sealing the piston ring gaps should be positioned at 180 intervals.
Use a universal tool to carefully insert the piston into the cylinder (first lubricate the inside of the cylinder with engine oil). Position the cylinder with the smallest valve recess is on the side of the exhaust port.
Remove
Remove any deposits and degrease the contact surfaces of the crankcase half and the cylinders.
Check for the presence of the cylinders centring dowels (b) and the o-ring (c) on the base.
Apply sealant to the gasket (5) then locate the gasket on the crankcase.
Using the cap 88713.1920, Fit the o-rings (a) on each stud bolt and guide them into their seats in the crankcase.
Bring the connecting rod small end close to tdc and slide the barrel-piston assembly (1-10) onto the crankcase studs.
Push the connecting rod small end into the piston close to the gudgeon pin (3) bore. Lubricate and insert the gudgeon Pin.
The gudgeon pin (3) must slide smoothly in the connecting rod small end bush and in the piston (1).
Close the crankcase opening with a cloth to prevent foreign objects from falling inside and then fit the retainer ring (2) as shown in the figure.
Important
Always fit new circlips (2) on reassembly.
Push the cylinder barrel (10) down until it seats against the crankcase.
Refit the bushes (12).
Fit the cylinder head gasket (11) over the studs. The side marked with the part number must be facing the cylinder head.
Note
The shape of the gasket prevents incorrect fitting, provided that the coolant flow holes are aligned with those on the cylinder.
Repeat the procedure for the other cylinder and refit the cylinder heads (sect. 9 - 4.5, Refitting the cylinder head assemblies).
In case they have not been assembled, apply prescribed threadlocker to unions (6) and tighten them to a torque of 25 nm (min. 23 Nm - max. 27 Nm) (sect. 3 - 3, Engine torque settings).
Fit the tubes (8) and (9) and tighten clamps (7) to a torque of 2.5 Nm (min. 2 Nm - max. 3 Nm) (sect. 3 - 3, Engine torque settings).
Removal of the gearchange control
Loosen and remove the pivot screw (4) securing the gearchange pedal (1) and
recover the washer (9) and the o-ring Seals (5).
Loosen and remove the screw (7) securing the gearchange lever (8) to the gear
selector shaft.
Withdraw the lever (8) complete with the gearchange control assem ...
Refitting the front footrests
Note
The assembly of the front footrests is described only for the right one
(2) but it is the same also for the left one.
Place the spring (4) bringing the end (a) onto the footrest (2).
Place the footrest (2) in the correct position, by inserting the end (c) of the
spring (4) in the hole ...
Refitting the starter motor gear
Position the washer (20) and the gear (19) in the pin (21) and take the pin
into contact with the crankcase half.
...