Vespa GTS Super 300 ie - Service manual > Inspecting the springs and half-cones

• Check that the upper and lower supporting spring washers, the cotters and the oil seal show exhibit no signs of abnormal wear. Replace a component when worn.

• Measure the unloaded spring length.

N.B.

TO MEASURE WEAR LIMITS AND COUPLING CLEARANCES, SEE THE SPECIFICATIONS CHAPTER.

Refitting the valves

• Lubricate the valve guides with engine oil.
• Place the valve spring supports on the head.
• Using the special punch, fit the four valve seal rings.
• Fit the valves, the springs and the caps. Using the appropriate tool with adapter, compress the springs and insert the cotters in their seats.

N.B.

DO NOT CHANGE THE POSITIONS THE VALVES ARE FITTED IN FIT THE VALVE SPONGES WITH THE REFERENCE COLOUR ON COTTER SIDE (TURNS WITH GREATER PITCH).

Specific tooling
  020306Y Punch for assembling valve seal rings
  020382Y Valve cotters equipped with part 012 removal tool
  020382Y011 adapter for valve removal tool

Inspecting the cam shaft

N.B.

TO MEASURE WEAR LIMITS AND COUPLING CLEARANCES, SEE THE SPECIFICATIONS CHAPTER.

Refitting the head and timing system components

• Refit the lower timing chain sprocket wheel on the crankshaft, with the chamfer facing the insertion side.
• Loop the timing chain around the sprocket on the crankshaft.
• Fit the chain tensioner slider from the cylinder head side.
• Fit the spacer and the screw fastener.
• Tighten the screws to the prescribed torque.
• Fit the pins and rocking levers.
• Lubricate the two rocking levers through the holes at the top.
• Lubricate the 2 bearings and insert the camshaft in the cylinder head with the cams corresponding to the rocking levers.
• Insert the retention plate and tighten the two screws shown in the figure to the prescribed torque.
• Refit the spacer on the camshaft.

• Rotate the engine so that the piston is at top dead centre, using the reference marks on the flywheel and the crankcase.
• Holding this position insert the chain on the camshaft control pulley.
• Insert the pulley on the camshaft while keeping the reference 4V in correspondence with the reference mark on the head.
• Fit the counterweight and tighten the clamping screw to the prescribed torque.
• Fit the end-stop ring on the automatic valve-lifter cam and fit the automatic valve-lifter cam to the camshaft.
• Fit the automatic valve lifter return spring.
• During this operation the spring must be loaded by approximately 180º.
• Fit the automatic valve-lifter retaining dish, using the counterweight screw fastener as a reference.
• Tighten the clamping screw to the prescribed torque.
• Set the tensioner cursor in the rest position.
• Fit the chain tensioner on the cylinder, using a new gasket, and tight the two screws to the prescribed torque.
• Insert the chain tensioning screw, together with the spring and washer, tightening it to the prescribed torque.
• Adjust the valve clearance.
• Fit the spark plug.

Electrode distance 0.8 mm

N.B.

GREASE THE END STOP RING TO PREVENT IT COMING OUT AND FALLING INTO THE ENGINE.

Locking torques (N*m)
Timing chain tensioner support screw 11 to 13
Spark plug 12 ÷ 14 Starter ground screw 7 to 8.5
Timing chain tensioner slider screw 10 to 14
Starter counterweight support screw 11 to 15
Timing chain tensioner central screw 5 to 6
Camshaft retention plate screw 4 to 6

• Fit the timing chain guide slider.
• Insert the centring dowel between the cylinder head to the cylinder, fit the cylinder head gasket and the cylinder head.
• Lubricate the stud bolt threading.
• Tighten up the nuts to an initial pre-torque of 7+-1 N*m
• Tighten up the nuts to a second pre-torque of 10 +-1 N*m
•  Rotate by an angle of 270º
• To carry out the operations described above, follow the tightening sequence in the figure.

• Fit the two screws on the outside of the timing chain side and tighten them to the specified torque.

N.B.

BEFORE INSTALLING THE HEAD, MAKE SURE THAT THE LUBRICATION CHANNEL IS CLEAN USING A COMPRESSED AIR JET.

Locking torques (N*m)
Timing chain tensioner support screw 11 to 13

Refitting the rocker-arms cover

• Refit the cylinder head cover and tighten the 5 clamping screws to the prescribed torque.
• Make sure the gasket is positioned properly.

Locking torques (N*m)
Tappet cover screws 6 - 7 Nm

Refitting the intake manifold

• Fit the intake manifold and do up the three screws.

Locking torques (N*m)
Intake manifold screws 11 ÷ 13

See also: