Suzuki Baleno Manual page 1597

6A3-58 ENGINE MECHANICAL (J18 TYPE ENGINE)
Cylinder Head
D 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 decarbon-
ing. The same applies to valves and valve seats, too.
D Check cylinder head for cracks in intake and exhaust ports, com-
bustion chambers, and head surface at a total of 6 locations. If
distortion limit, given below, is exceeded, correct gasketed sur-
face with a surface plate and abrasive paper of about #400 (Wa-
terproof silicon carbide abrasive paper):
Place 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 re-
duced power output.
Limit of distortion: 0.05 mm (0.002 in.)
D Distortion of manifold seating faces:
Check seating faces of cylinder head for manifolds, using a
straightedge and thickness gauge, in order to determine wheth-
er these faces should be corrected or cylinder head replaced.
Limit of distortion: 0.10 mm (0.004 in.)