Engine – Cub Cadet Yanmar 3TNV72 User Manual
Page 125

ENGINE
6-26
TNV IDI Service Manual
Cylinder Head
Inspection of Rocker Arm Assembly
Rocker Arm Shaft Hole Diameter
Use a telescoping gauge and micrometer to 
measure the inside diameter of all the rocker arm 
support brackets and the rocker arms 
(Figure 6-12). Record the measurements. See 
Rocker Arm and Shaft on page 6-7 for the service 
limit.
Inspect contact areas (Figure 6-12, (1)) for 
excessive wear or damage.
Figure 6-12
Rocker Arm Shaft Outside Diameter
Use a micrometer to measure rocker arm shaft 
diameter. Measure at each rocker arm location in 
two directions 90° apart (Figure 6-13). Record the 
measurements. See Rocker Arm and Shaft on 
page 6-7 for the service limit.
Figure 6-13
Inspection of Valve Guides
Visually inspect the valve guides for distortions, 
scoring or other damage. 
Note: Measure valve guides while they are
installed in cylinder head.
Use a telescoping gauge and micrometer to 
measure the inside diameter of the valve guide. 
Measure in three places and 90° apart 
(Figure 6-14). Record the measurements. See 
Intake / Exhaust Valve and Guide on page 6-6 for 
the service limit. Replace valve guides if not within 
specification.
Figure 6-14
Inspection of Cylinder Head
Cylinder Head Distortion
Put the cylinder head flat and inverted (combustion 
side up) on the bench. Use a straightedge and 
feeler gauge to measure cylinder head distortion 
(Figure 6-15). Measure diagonally and along each 
side. Record the measurements. See Cylinder 
Head on page 6-5 for the service limit.
Figure 6-15
0001916
(1)
(1)
0001952
0001869
0000192
TNV_IDI_ServiceManual_(3TNV72 for YN only).book 26 ページ 2007年11月29日 木曜日 午後2時58分
