Generac Power Systems GTH760 Service Manual page 60

SECTION 12: PISTON, RINGS & CONNECTING ROD INSPECTION & ASSEMBLY
Figure 12-4. Checking Ring End Gap
Figure 12-5. Check Piston Pin Bore
CHECKING PISTON PIN AND CONNECTING ROD
1. Check piston pin, Figure 12-6.
a. Replace if less than 19.97mm (.7862") or if it is .01mm (.0005")
out of round.
2. Check connecting rod bearings (see Figure 12-7).
Note: If piston pin or crankpin bearing ends are scored or worn the
connecting rod must be replaced.
Figure 12-6. Check Piston Pin
PISTON PIN BEARING
Figure 12-7. Check Rod Bearings
ASSEMBLE PISTON AND CONNECTING ROD
Lubricate parts with engine oil and assemble #1 piston and connect-
ing rod, Figure 12-8.
1. Notch or casting mark on the piston top must face towards the
flywheel.
2. Number "1" on connecting rod must face PTO side (opposite notch
or casting mark on piston).
a. Install piston pin locks with needle nose pliers.
Lubricate parts with engine oil and assemble #2 piston and connect-
ing rod, Figure 12-9.
1. Notch or casting mark on the piston top must face towards the
flywheel.
2. Number "2" on connecting rod must face PTO side (away from the
flywheel).
a. Install piston pin locks with needle nose pliers.
12-2
CRANKPIN BEARING