Generac Power Systems 941-2 Service Manual page 52

Section 2.4
CRANKSHAFT AND CAMSHAFT
CAMSHAFT INSPECTION
Carefully inspect the entire camshaft for wear, nicks,
damage. All areas indicated in Figure 4 should be
checked for wear.
Figure 4. Points to Check on Camshaft
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)
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.
• Inspect timing gear teeth for chipping or cracking. If
the timing gear is damaged, the crankshaft assem-
bly must be replaced.
Page 2.3-6
• 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.
• Carefully measure the outside diameter (O.D.) of
the crankpin, crankshaft journal at flywheel end,
and crankshaft journal at PTO end. Replace the
crankshaft if it is worn smaller than the stated limits.
NOTE: DO NOT regrind the crankpin to any small-
er diameter. Undersize connecting rods are NOT
available for the GV-220 engines.
• 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 (29.99-30.01mm)
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
Figure 5. Points to Check on Crankshaft
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