Briggs & Stratton 130G00, Repair Manual

Page: 69 / 112

Not for
Reproduction
77
Hone (Resize) Cylinder Bore
NOTE: If lacking the necessary tools, skills, or experience,
take crankcase to a qualified machine shop for cylinder
boring.
NOTE: Resize the cylinder bore if worn 0.003 inches (0.08
mm), or is 0.0015 inches (0.04 mm) out-of-round. Always
resize exactly 0.020 inches (0.51 mm) larger than the
standard bore diameter to ensure service oversize piston
and rings have the proper clearances.
1. Tape over governor gear to keep out honing grit and
other debris.
2. Obtain a three blade rigid hone with 220 grit aluminum
oxide stones.
3. To prevent damage to stones, check the top and bottom
of the cylinder bore for burrs. Remove any burrs with a
fine-tooth file.
4. Securely fasten cylinder to a heavy iron bracket or
suitable honing fixture and place on level floor.
5. Place hone drive shaft in chuck of portable, variable
speed drill and tighten.
6. Using a suitable honing oil, liberally lubricate cylinder
bore and stones.
7. Place hone in middle of cylinder bore.
8. Tighten adjusting knob until stones fit snugly against
cylinder wall.
9. Activate drill and move hone up and down lower end
of cylinder bore. The cylinder is not worn at the bottom,
so it will help to keep hone straight in the bore. As the
bottom of the bore increases in diameter, gradually
increase each stroke until hone travels the full length
of the bore.
NOTE: Hone cylinder bore with a drill speed of 300 to
700 RPM maximum at 40-60 strokes per minute.
NOTE: Do not extend hone more than 3/4-1 inches
(19.05-25.4 mm) from either end of the bore or stones
may be damaged.
10. As cutting tension decreases, stop hone and tighten
adjusting knob.
11. Frequently stop to examine the cylinder bore and take
measurements.
NOTE: Hone cylinder bore about 0.0005 inches (0.01
mm) larger than the desired size to allow for contraction
as the cylinder cools.
12. Lubricate hone frequently to prevent build up on stones.
13. Stop frequently to examine the cylinder bore and take
measurements.
14. When cylinder is resized to within 0.0015 inches (0.04
mm) of the desired size, use finishing stones to achieve
the final size and produce the correct cross hatch
pattern. See
Deglaze (Recondition) Cylinder Bore, steps
3-7.
NOTE: An improper cross hatch pattern or too fine a
hone will result in insufficient oil retention and possible
piston seizure and/or high oil consumption.
Clean Crankcase and Cylinder Bore
1. Thoroughly wash crankcase and cylinder bore with a
non-volatile cleaning solution or solvent.
2. To loosen all abrasive particles and residual grit,
thoroughly scrub cylinder bore with a stiff bristle brush
using liquid dishwashing soap and hot water.
3. Thoroughly rinse cylinder bore with hot running water.
4. Repeat washing and rinsing until all traces of honing
grit are gone. Continue cleaning until a clean cloth
shows no evidence of dirt or debris.
NOTE: Honing grit, which appears as a grey residue,
is highly abrasive and will cause rapid cylinder, piston
and ring wear resulting in premature engine failure.
5. Hot rinse the crankcase and dry with moisture free
compressed air.
6. Verify that breather passage, intake and exhaust ports,
and governor gear assembly are completely clean and
free of dirt and grit.
7. Verify that oil hole between the tappet bores is clean
and open.
8. Lightly lubricate cylinder bore with clean engine oil.
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