Checking The Timing Chain And Camshaft Sprocket; Checking The Timing Chain Tensioner; Installing The Cylinder Head - Yamaha SR400 2014 Service Manual

Camshaft lobe dimensions
Lobe height (Intake)
38.860–38.960 mm
(1.5299–1.5339 in)
Limit
38.850 mm (1.5295 in)
Base circle diameter (Intake)
32.170–32.270 mm
(1.2665–1.2705 in)
Limit
32.160 mm (1.2661 in)
Lobe height (Exhaust)
38.890–38.990 mm
(1.5311–1.5350 in)
Limit
38.880 mm (1.5307 in)
Base circle diameter (Exhaust)
32.210–32.310 mm
(1.2681–1.2720 in)
Limit
32.200 mm (1.2677 in)
3. Check:
• Rocker arm and rocker arm shaft oil passage
Obstruction  Blow out with compressed air.
EAS23870
CHECKING THE TIMING CHAIN AND
CAMSHAFT SPROCKET
1. Check:
• Timing chain
Damage/stiffness  Replace the timing
chain, camshaft sprocket, and crankshaft
sprocket as a set.
2. Check:
• Camshaft sprocket
• Crankshaft sprocket
More than 1/4 tooth wear "a"  Replace the
camshaft sprocket, crankshaft sprocket, and
timing chain as a set.
a
2
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket or crankshaft sprocket
EAS24200

CHECKING THE TIMING CHAIN TENSIONER

1. Check:
• Timing chain tensioner
Cracks/damage/rough movement  Re-
place.
EAS24230

INSTALLING THE CYLINDER HEAD

1. Install:
• Cylinder head gasket
• Dowel pin
2. Install:
• Cylinder head "1"
5-9
CYLINDER HEAD
1
New
b