Cylinder Head Inspection

Reference: VALVES AND CYLINDER HEADS REMOVAL AND INSTALLATION 

Reference: VALVES AND CYLINDER HEADS DISASSEMBLY AND REASSEMBLY 

• Remove all carbon from combustion chambers.
  NOTE: Do not use any sharp-edged tool to scrape off carbon. Be careful not to scuff or nick metal surfaces when de-carboning. The same applies to valves and valve seats, too.
  Fig 1: Removing Carbon From Combustion Chambers

  Courtesy of SUZUKI OF AMERICA CORP.
• Check cylinder head for cracks on intake and exhaust ports, combustion chambers, and head surface.

  Using straightedge (1) and thickness gauge (2), check flatness of gasketed surface at a total of 6 locations. If distortion limit, given below, is exceeded, correct gasketed surface with a surface plate and abrasive paper of about #400 (Waterproof silicon carbide abrasive paper): Place abrasive paper on and over surface plate, and rub gasketed surface against paper to grind off high spots. Should this fail to reduce thickness gauge readings to within limit, replace cylinder head.

  Leakage of combustion gases from this gasketed joint is often due to warped gasketed surface: such leakage results in reduced power output.

  Cylinder head gasketed surface distortion 

  Limit: 0.05 mm (0.002 in.) 

  Fig 2: Checking Cylinder Head Gasket Surface Distortion

  Courtesy of SUZUKI OF AMERICA CORP.
• Distortion of manifold seating faces

  Check seating faces of cylinder head for manifolds, using a straightedge (1) and thickness gauge (2), in order to determine whether these faces should be corrected or cylinder head replaced.

  Manifold seating surface distortion 

  Limit: 0.10 mm (0.004 in.) 

  Fig 3: Checking Distortion Of Manifold Seating Faces

  Courtesy of SUZUKI OF AMERICA CORP.