Generac Power Systems GTH1000, Service Manual

Page: 61 / 74

12-3
SECTION 12: PISTON, RINGS & CONNECTING ROD INSPECTION & ASSEMBLY
CASTING MARK MUST
FACE FLYWHEEL SIDE
NUMBER MUST
FACE PTO SIDE
Figure 12-8. Assemble #1 Rod And Piston
ASSEMBLE PISTON RINGS TO PISTON
Install piston rings using ring expander when installing center and top
compression rings. See Figure 12-10.
1. Install oil ring expander.
a. Install lower oil scraper ring.
a. Install upper oil scraper ring.
2. Install center compression ring with dimple up.
3. Install top compression ring with dimple up.
CASTING MARK MUST
FACE FLYWHEEL SIDE
NUMBER MUST
FACE PTO SIDE
Figure 12-9. Assemble #2 Rod And Piston
TOP COMPRESSION RING
(DIMPLE MUST FACE UP)
CENTER COMPRESSION RING
(DIMPLE MUST FACE UP)
OIL RING EXPANDER
AND SCRAPER RINGS
PISTON
RING
GROOVES
0.25-0.50 mm
(0.0098-0.0197 in.)
DIMPLE DENOTES
UP-SIDE OF RING.
(TOWARDS TOP OF
PISTON)
Figure 12-10. Piston Ring Installation
12