Valves & Valve Guides Inspection: Valves

• Remove all carbon deposits from valves.
• Inspect each valve for wear, burn or distortion at its face and stem, replace as necessary.
• Measure thickness of valve head. If measured thickness exceeds limit, replace valve.

Valve specification 

Fig 1: Valve Specification Chart

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Fig 2: Identifying Valve Head Thickness & Valve Face Angle

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• Inspect valve stem end face for pitting and wear. If pitting or wear is found there, valve stem end may be resurfaced, but not too much to grind off its chamber. When it is worn out too much that its chamber is gone, replace valve.
  Fig 3: Identifying Valve Stem End Face

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• Check each valve for radial with a dial gauge and "V" block. To check runout, rotate valve slowly. If runout exceeds its limit, replace valve.

Valve head radial runout 

1. Limit:  0.08 mm (0.003 in.)
Fig 4: Checking Valve Head Radial Runout
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Seating contact width 

Create contact pattern on each valve in the usual manner, i.e. by giving uniform coat of marking compound to valve seat and by tapping seat with valve head. Valve lapping tool must be used when lapping valves.

Pattern produced on seating face of valve must be a continuous ring without any break, and the width of pattern must be within specified range.

Standard seating width revealed by contact pattern on valve face 

1. In and Ex:  1.1 - 1.3 mm (0.0433 - 0.0512 in.)

Fig 5: Identifying Valve Seating Contact Width

Courtesy of SUZUKI OF AMERICA CORP.