Cylinder Head, Valves - Service Information; Cylinder Head, Valves Troubleshooting - Honda XLR200R Service Manual

7. CYLINDER HEAD, VAlVES
SERVICE INFORMATION .................................. 7 - 1
CYLINOER HEAD DISASSEMBLY & ASSEMBLY. 7 - 5
TROUBLESHOOTING ........................................ 7 - 1 CYLINDER HEAD INSTALLATION ..................... 7 - 6 -
CYLINDER HEAD REMOVAL. .........•..............•••.. 7 - 2
SERVICE INFORMATION
Cylinder head maintenance should be done after the e,ngine has been removed from the frame.
When removing the cylinder head, do not damage the fins or the surfaces with your screwdriver.
During assembly, apply molybden on camshaft bearing and cam lobe s~rfaces for
initial
lubrication.
The engine oil for cam shaft lubrication passes through the cylinder head oil canal. When assembling the cylinder h e a d , .
clean the oil passage.
Clean all disassembled parts with clean solvent and dry them using compressed air before inspection.
TROUBLESHOOTING
Mqst cylinder head defects can be detected generally by measuring compression pressure or by listening to the sound
-of
the engine top end.
When encountering starting defects or defects at low speed, check the crankcase breather tube fot smoke. If there is
smoke, this is an indication of piston ring wear out, damage or stick.
Valve-related parts should be adjusted to fit to their standard setting.
Compression Pressure is Too Low
Incorrect valve adjustment
Burnt or worn-out valve
Incorrect valve timing
Broken valve spring
Valve seat adherence defect
Blown-out cylinder head gasket
Cylinder head warping or cracking
Improperly installed spark plug
Compression Pressure is Too High
Excessive- carbon build-up on piston head or combustion
chamber
White Smoke from Muffler
Valve guide or valve stem wear out
• Valve stem seal damage
Abnormal Noise
Incorrect valve adjustment
Sticking valve or broken valve s:pring
Camshaft worn or damage
Cylinder, piston damage
Poor Idling
• Low compression pressure
7-1