Crankcase
{l) Inspect the outside and inside surfaces for evidence
of cracking. Visually examine the cylinder bores
for scuffing, rusting, erosion or any abnormal
wear. Using a straightedge, check the top face
(for mating with cylinder head), front face (for
mating with front plate) and rear face (for mating
with rear plate) for flatness.
(2) Make sure that the top face of the crankcase is
flat within the standard specified below. If the
standard is found to be exceeded, reface the top
by using a surface grinder to make it flat within
the specified standard.
Specifications
Item
Standard
Warpage of crankcase
0.05, max.
gasketed surface
Crankshaft
(1) Journals
(0.0020)
Unit: mm (in.)
Repair
limit
0.20
(0.0079)
(a) Inspect each journal for surface flaws such as
roughing, scratches, pitting and bums, and, as
necessary, repair the journals by grinding to the
next undersize or replace the crankshaft.
(b) Mike each journal to take a total of four read
ings to determine the wear, out-of-round and
taper (cylindricity). If any of the limits is
exceeded, repair by grinding to the next under
size or replace the crankshaft.
Checking crankcase top for flatness
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0
1 2
Positions for miking journal
