Generac Power Systems NP-40G - Manual (Page 49)

Section 2.4- CRANKSHAFT AND CAMSHAFT
Camshaft Inspection (Continued)
The following should be measured carefully to check
for wear:
MAIN CAMSHAFT BEARING DIAMETER
(FLYWHEEL END)
DESIGN DIAMETER: 1.022-1.023 Inch (25.96-25.98mm)
WEAR LIMIT: 1.020 Inch (25.91mm) Minimum
MAIN CAMSHAFT BEARING DIAMETER
(PTO END) GN-190 ONLY
DESIGN DIAMCTER: 1.022-1.023 Inch (25.96-25.98mm)
WEAR LIMIT: 1.020 Inch (25.91mm) Minimum
MAIN CAMSHAFT BEARING DIAMETER
(PTO END) GN-220 ONLY
DESIGN DIAMETER: 1.297-1.298 Inch (32.96-32.98mm)
WEAR LIMIT: 1.295 Inch (32.89mm) Minimum
CAMSHAFT BEARING BORE IN CRANKCASE
DESIGN DIAMETER: 1.024-1.025 Inch (26.00-26.03mm)
WEAR LIMIT: 1.026 Inch (26.06mm) Maximum
CAMSHAFT BEARING BORE IN CRANKCASE COVER
DESIGN DIAMETER: 1.299-1.300 inch (33.00-33.03mm)
WEAR LIMIT: 1.302 Inch (33.06mm) Maximum
CAM LIFT
DESIGN LIFT: 0.210-0.212 Inch (5.34-5.38mm)
WEAR LIMIT: 0.206 Inch (5.24mm) Minimum
Crankshaft Inspection:
CRANKSHAFT PROPER:
Use a commercial solvent to clean the crankshaft.
After cleaning, Inspect the crankshaft as follows:
□ Inspect keyways in crankshaft, make sure they are
not worn or spread. Remove burrs from edges of
keyway, to prevent scratching the bearing.
D Inspect timing gear teeth for chipping or cracking. If
the timing gear Is damaged, the crankshaft assembly
must be replaced.
G Inspect the crankpin for damage, nicks, scratches,
etc. Small nicks and scratches may be polished out
using fine emery cloth. ALL EMERY RESIDUE MUST
BE REMOVED. Use a solvent (such as kerosene) to
remove emery residue.
D Carefully measure the outside diameter (O.D.) of the
crankpin, crankshaft journal at flywheel end, and
crankshaft journal at PTO end. Replace the crank­
shaft if it is worn smaller than the stated limits.
NOTE: DO NOT regrInd the crankpin to any smaller
diameter. Undersize connecting rods are NOT
available for the GN-190 or GN-220 engines.
G Inspect oil passage. Use a length of wire to make
sure it Is open. Inspect threaded ends of crankshaft.
CRANKPIN OUTSIDE DIAMETER
DESIGN DIAMETER: 1.180-1.181 INCH (29.99-30.01 MM)
WEAR LIMIT: 1.179 inch (29.96mm) Minimum
CRANKSHAFT BEARING JOURNAL (FLYWHEEL END)
DESIGN DIAMETER: 1.102-1.103 Inch (28.000-
28.012mm)
WEAR LIMIT: 1.100 inch (27.95mm) Minimum
CRANKSHAFT BEARING JOURNAL (PTO END)
DESIGN DIAMETER: 1.102-1.103 inch (28.000-
28.012mm)
WEAR LIMIT: 1.186 inch (27.95mm) Minimum
CRANKSHAFT SLEEVE BEARING:
A sleeve bearing (Figure 6) Is pressed into the crank­
shaft bore of the crankcase. A bearing is NOT provided
for the crankshaft bore in the crankcase cover.
Inspect the sleeve bearing In the crankcase for dam­
age. Measure the inside diameter (I.D.) of the sleeve
bearing. Replace any sleeve bearing that Is worn exces­
sively. Press out the old bearing, press a new bearing
into place.
CRANKSHAFT SLEEVE BEARING
DESIGN DIAMETER: 1.104-1.106 inch (28.044-
28.099mm)
WEAR LIMIT: 1.107 inch (28.129mm) Maximum
Check the crankshaft bearing bore in the crankcase
cover. If limits are exceeded, replace the crankcase
cover.
CRANKSHAFT BEARING BORE IN CRANKCASE
COVER
DESIGN DIAMETER: 1.104-1.105 inch (28.040-
28.065mm)
WEAR LIMIT: 1.106 inch (28.092mm) Maximum
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