General; Valve Clearance Adjustment - BRP BOMBARDIER DS250 2006 Shop Manual

Section 03 ENGINE
Subsection 08 (CYLINDER HEAD)

GENERAL

When diagnosing an engine problem, always per-
form a leak test. Refer to ENGINE LEAK TEST.
Always place the vehicle on level surface.
Always disconnect the negative wire from the bat-
tery before working the engine.
During assembly/installation, use the torque val-
ues and service products as in the exploded
views.
WARNING
Torque wrench tightening specifications
must strictly be adhered to.
Locking devices (ex.: locking tabs, elastic
stop nuts, self-locking fasteners, cotter pin,
etc.) must be installed or replaced with new
ones where specified. If the efficiency of
a locking device is impaired, it must be re-
newed.
When disassembling parts that are duplicated in
the engine, (valves, springs, etc.), it is strongly rec-
ommended to note their position and to keep the
parts of the same assembly as a "group". If you
find a defective component, it will be much easier
to find the cause of the failure among its group of
parts (for example, if you find a worn valve guide, a
bent spring could be the cause; it will be easier to
know which one of the springs is the cause and
to replace it). Besides, since parts are matched
together, it is a good practice to reinstall parts in
the same position.
Intake port/air filter contaminated (clogged) with
dirt, sand, etc. leads to worn valves, piston rings
and finally to loss of power.
CAUTION: In case of piston rings and/or valve
replacement, always clean the whole engine
and change oil.
VALVE CLEARANCE
ADJUSTMENT
NOTE: Engine temperature must be below 35°C
(95°F) to perform valve adjustment.
70
Preparation for Adjustment with
Engine in Vehicle
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Remove fuel tank, air injection pipe upper screws,
valve cover and spark plug.
Remove cylinder head side cover, CVT cover and
magneto access plug.
Positioning Crankshaft and Camshaft
Turn drive pulley clockwise to bring piston at TDC.
Align TDC mark as shown.
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TDC MARK BESIDES THE "T" ALIGNED
Check if marks are aligned on camshaft gear as
shown. Otherwise, continue turning drive pulley
until crankshaft and camshaft marks are properly
positioned.
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