Derbi Rambla 250 Manual page 115

Engine
Refitting the piston rings
Sealing rings fitting
- Place the oil scraper spring on the piston.
- Fit the oil scraper ring keeping the gap opposed
to the spring union and the word "top" facing the
piston crown. In any case, the chamfered side of
the must be facing the piston crown.
- Fit the middle piston ring with the identification
letter or the word "top" facing the piston crown. In
any case, the tapered side of the ring must be fac-
ing opposite the piston crown.
- Fit the top piston ring with the word "top" or the
reference mark facing the piston crown.
- Offset the piston ring gaps on the three rings by
120º as shown in the figure.
- Lubricate the components with engine oil.
- 250 engines are fitted with top ring with an L sec-
tion.
NOTE
THE 2 PISTON RINGS ARE MADE WITH A TAPERED CY-
LINDRICAL CONTACT SECTION. THIS IS TO OBTAIN A
BETTER BEDDING.
Refitting the cylinder
- Fit the cylinder base gasket of the chosen thick-
ness.
- Using the fork support and the retaining clamp,
fit the cylinder as shown in the figure.
NOTE
BEFORE FITTING THE CYLINDER, CAREFULLY BLOW
AIR INTO THE LUBRICATION DUCT AND LUBRICATE THE
CYLINDER LINER.
Specific tooling
ENG - 115