Cylinder Head - Description
The engine is fitted with an aluminium alloy cylinder head, which carries the
camshaft, valves and spark plugs. The cylinder head is cast as a single entity, to
which various components are permanently added after machining.
A silent running camshaft drive chain drives the single overhead camshaft, which
runs directly in the cylinder head without additional bearings.
The crankshaft drives an idler gear, which in turn drives the camshaft drive chain. The
idler gear, and therefore the camshaft rotates in the opposite direction to the
crankshaft.
The engine is fitted with a camshaft drive chain hydraulic tensioner. The tensioner is
fed oil via a gallery in the crankcase. The combination of oil pressure and spring
pressure pushes the plunger against the tensioner blade which tensions the
camshaft drive chain. The hydraulic tensioner has an oil pressure relief valve located
in the plunger that is set to open between 12 - 16 bar. The chain is guided by two
nylon tensioner blades. The rubbing blade is located in the cylinder barrel by lugs on
the blade. The cylinder head must be removed to remove this blade. The tensioner
blade is secured to the cylinder head by two bolts at its upper end, and its lower end
rests on the tensioner plunger.
Camshaft, valve, valve shim and valve seat wear affect the valve clearances. The
effect of this wear is to change the clearance between the rocker and the adjustment
shim, causing engine noise and/or improper running. If the valve clearances are
incorrect, permanent damage to components in the valve train will take place and
engine performance will be affected.
Oil is supplied to the cylinder head by an internal passageway inside the engine.
Once it arrives at the cylinder head, it is passed through a restrictor, and is then
delivered to the camshaft bearing journals along grooves and bolt holes in the
camshaft frames. The camshaft lobes are splash fed by oil coming from the rocker
arms.
Camshaft Drive Chain Tensioner - Removal
WARNING
Service Manual - Scrambler 1200 XC
160 of 640
Summary of Contents for Scrambler 1200 XC
Page 67: ...ckju Evaporative Hose Routing Service Manual Scrambler 1200 XC 67 of 640 ...
Page 134: ...Exploded View Clutch Cover Service Manual Scrambler 1200 XC 134 of 640 ...
Page 135: ...Exploded View Alternator Cover Service Manual Scrambler 1200 XC 135 of 640 ...
Page 159: ...Exploded View Cylinder Head Service Manual Scrambler 1200 XC 159 of 640 ...
Page 291: ...Exploded View Gear Selector Service Manual Scrambler 1200 XC 291 of 640 ...
Page 333: ...Oil Circuit Diagram Service Manual Scrambler 1200 XC 333 of 640 ...
Page 374: ...Exploded View Fuel Pump Service Manual Scrambler 1200 XC 374 of 640 ...
Page 375: ...Exploded View Fuel Rail Throttles and Injectors Service Manual Scrambler 1200 XC 375 of 640 ...
Page 377: ...Exploded View Exhaust System Service Manual Scrambler 1200 XC 377 of 640 ...
Page 378: ...Exploded View Evaporative System if fitted Service Manual Scrambler 1200 XC 378 of 640 ...
Page 619: ...Service Manual Scrambler 1200 XC 619 of 640 ...