Inspection; Installation - Yamaha TDM850 1996 Service Manual

CYLINDER HEAD

INSPECTION

1. Eliminate:
S Carbon deposit
(from combustion chamber)
Use rounded scraper.
NOTE:
Do not use a sharp instrument to avoid damaging
or scratching:
S Spark plug threads
S Valve seat
2. Inspect:
S Cylinder head
Scratches /Damage ! Replace.
3. Measure:
S Cylinder head warpage
Out of specification ! Resurface.
Cylinder head warp limit:
Less than 0.03 mm
Warp limit measurement and resurfacement
steps:
S Hold a straight edge and a thickness gauge to
the cylinder head.
S Measure the warpage.
S If the warpage is out of specification, resurface
the cylinder head.
S Place a 400 X 600 grit wet sandpaper on the sur-
face plate, and resurface the head using a figure-
eight sanding pattern.
NOTE:
Rotate the head several times to avoid removing
too much material from one side.

INSTALLATION

1. Install:
S Dowel pins
S Cylinder head gasket
S Cylinder head
NOTE:
S Apply the engine oil onto the nut threads.
S Tighten the nuts in a crisscross pattern.
4-14
ENG
New
Nut 40 Nm (4.0 mSkg)
Bolt 10 Nm (1.0 mSkg)