TOP Perfomance PIAGGIO 50 4T Manual Del Usuario página 14

a hand or by means of compression tool) by passing the timing
chain through the suitable cylinder cavity, and then push the
cylinder fully against the casing.
– Fit the chain guide sliding block by positioning it in the proper
seat.
– Fit the two dowels and the new head gasket.
– Position the head on the cylinder and make use of an iron wire
to pass the timing chain through the proper head cavity.
– Slightly smear the four bolts (M6) threads with engine oil.
– Tighten the four M6 nuts in a crossed pattern and with a
tightening torque of 12 Nm.
– Tighten the two side screws (M6) securing head to crankcase
with tightening torque of 10 Nm.
– Bring the engine at the top dead centre during the compression
stroke.
– Align the second tooth on the fl ywheel with the pick-up sensor
tooth by turning the crankshaft clockwise using the generator
rotor nut (Fig. 2).
– Fit the timing chain on the gear.
– Insert the gear on the camshaft and align its reference point
(Fig. 1) with the head reference and tighten with a tightening
torque of 20 Nm.
– Recheck the alignment of the crankshaft and camshaft timing
reference points.
– Should it be incorrect repeat the operation.
A wrong timing would cause serious damages to the engine
– Remove the iron wire from the timing chain.
•
Chain tightener assembly
– Unscrew the M6 screw on the top of the chain tightener (pay
attention to the O-ring and internal spring).
– After having removed the spring, push on the lock lever to
press the cursor of the chain tightener down.
– Fit the chain tightener on the cylinder and spread a sealing
paste fi lm on the two screws. Use the new gasket provided
with the kit.
– Insert the spring inside the chain tightener tighten the M6
screw with a tightening torque of 10 Nm.
– Turn the crankshaft by some turns and during the compression
stroke bring the engine again at the top dead centre; then check
the correct alignment of camshaft with the head reference. If it
is wrong, realign them.
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