Briggs & Stratton 130G00, Repair Manual

Page: 59 / 112

Not for
Reproduction
PISTON AND CONNECTING ROD
Disassembly
1. Insert small pick into pick lock groove and pull piston
pin lock ring out of pin boss groove on one side of
piston. Discard lock ring.
CAUTION
Always wear proper eye protection when removing
piston pin lock ring. Slippage can propel the ring with
enough force to cause eye injury.
2. Push piston pin toward open pin boss to remove from
piston and upper connecting rod.
3. Obtain the Piston Ring Expander (Part No. 19340).
CAUTION
Always wear proper eye protection when removing
compression and oil wiper rings. Slippage may propel
the ring with enough force to cause eye injury.
4. See Figure 58. Remove compression ring from the top
ring groove.
58
5. Remove oil wiper ring from the middle ring groove.
6. Remove oil control ring from the bottom ring groove.
Proceed as follows:
• Remove the expander spring.
59
• See Figure 59. Spiral or wind the upper steel rail
from the bottom ring groove into the middle ring
groove. Repeat action to move the rail into the top
ring groove and then off the piston.
• Repeat above step to remove the lower steel rail.
Cleaning
Piston
1. Do not sand blast or glass bead blast piston. Bead
blasting rounds the ring lands and will result in high oil
consumption and blow-by of exhaust gases. Blow-by
of exhaust gases contaminates the engine oil supply,
and reduces engine efficiency by weakening the
combustion seal necessary for efficient transfer of
energy to the piston.
2. To remove all carbon and combustion deposits, soak
the piston in a special detergent that will not corrode
aluminum. Maintain the temperature of the cleaning
solution well below 212° F. (100° C.).
3. Thoroughly rinse the piston and dry with moisture free
compressed air.
4. Thoroughly clean the three piston ring grooves of all
carbon deposits. A broken compression ring properly
ground to a sharp chisel-like edge can be used for this
purpose.
5. Verify that the piston pin lock ring groove is clean and
free of dirt and grime.
6. Clean oil drain back holes leading from the oil control
ring groove to the underside of the piston crown. Use
a soft bristle brush and compressed air to ensure
53
6