Suzuki Jimny Service Manual page 537

6A1-56 ENGINE MECHANICAL (M13 ENGINE)
• Check cylinder head for cracks on intake and exhaust ports,
combustion chambers, and head surface.
Using a straightedge and thickness gauge, check flatness of
gasketed surface at a total of 2 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.
Limit of distortion for surface of cylinder head piston side
0.03 mm (0.001 in.)
• Distortion of manifold seating faces:
Check seating faces of cylinder head for manifolds, using a
straightedge and thickness gauge, in order to determine
whether these faces should be corrected or cylinder head
replaced.
Limit of distortion for surface of cylinder head intake and
exhaust manifolds sides
0.05 mm (0.002 in.)