Vortex ROK DVS J, Owner'S Manual

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MAINTENANCE
DVS-Junior
24
4.6.6 CYLINDER CHECK AND MAINTENEANCE
10mm Tube Wrench
Torque Wrench
To avoid engine damage, a Vortex qualified mechanic
must perform inspection and honing.
Remove exhaust.
Remove spark plug. Remove the six head nuts and
relative washers.
Remove cylinder head by pulling it up carefully.
Remove the cylinder from the crankcase slowly. Once cylinder
is separate from crankcase, hold the connecting rod with the
other hand and pull the cylinder out totally by pulling it up
carefully.
Every time cylinder is removed we recommend changing
cylinder gasket.
Cylinder must be honed when cylinder/piston
clearance is more than 0.12mm or when ovalization is
more than 0.02 mm.
Change piston (see 4.6.7)
New piston cylinder/piston clearance must be 0.12mm.
REASEMBLING
Insert a new gasket on to the studs carefully and place it on the
crankcase surface flat.
Insert now the cylinder in the studs very carefully. With the
other hand close piston ring and inset the piston into the
cylinder. If piston ring is not closed totally, risk of damaging the cylinder and piston ring is very
high. Push the cylinder down firmly. Tight four cylinder nuts with torque wrench at 20Nm.
Insert cooper washer.
Install, carefully, the head onto the studs and check all o-rings are fitted in the right place. If any is
damaged, change it.
Install washers and nuts onto the studs and tight them manually. Now, by using a torque wrench
tighten them alternatively at 1,6 kgm.
Every time cylinder is honed or piston changed, the engine break-in procedure must be
performed.