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Part No. 890207 Form No. F021795E
Page 8 of 12
MAINTENANCE
MAINTENANCE 8
CHIPPER BLADE REMOVAL AND SHARPENING
Depending on the type and amount of wood being chipped, the
chipper blade will eventually get dull, losing it’s cutting ability.
Evidence of a dull blade is a noticeably reduced chipping ability or a
rough cut on end of branch.
Note: The chipper blade gap is factory set and should be checked
each time impeller is removed from engine crankshaft and reset if
required. If reassembly requires a different quantity of shim
washers, Billy Goat
® shim washer must be used.
Chipper blades are normal replaceable wear items.
DANGER Chipper blade is sharp.
Replace any damaged blade.
11. Using a 3/16" Allen wrench and 1/2" open end wrench, remove
chipper blade from impeller.
12. Sharpen blade by lightly grinding the cutting edge of the blade
at 40 degrees (see fig. 5). It is not necessary to remove all nicks
from the cutting edge.
CAUTION:
Be careful to avoid heat buildup
in the blade during sharpening. This will reduce it’s heat- treated
hardness properties and will reduce blade life. Evidence of too
much heat build-up is a change of color along sharpened edge.
13. The same chipper blade can be sharpened several times.
However, blade replacement is required when blade no longer
overhangs the chip relief hole in impeller back plate or if increased
vibration occurs (see fig. 5).
14. Chipper blade installation is in reverse order of removal.
40
o
Blade
Blade
INCORRECTCORRECT
15. To reinstall impeller, use a new impeller bolt and lockwasher and
use exactly the same crankshaft impeller shim washers as were
removed during disassembly (unless they were damaged).
However, your unit may or may not have required the use of shim
washers
.
16. Tighten impeller bolt. Torque impeller bolt to 50 Ft. Lbs. (68 N
.
m)
(see item 51 on page 11).
17. Slowly rotate impeller to insure proper chipper blade clearance.
Check to see that gap between chipper blade and anvil surface (on
lower side of housing top plate) measures between
0.040"(1.02mm) and 0.080"(2.03mm).
18. If gap is less than 0.040"(0.51mm), add shim washer 890130
(0.060"{1.52mm} thick) and/or 890131 (0.020"{1.02mm} thick),
whichever is required. If gap is more than 0.080"(2.03mm), remove
one or more shim washers as needed to obtain correct gap (see fig.
6 & fig. 7). The chipper will function at up to a maximum of
0.125"(3.18mm) gap.
EDGE OF CHIP
RELIEF HOLE
Fig. 5
Use only a qualified mechanic for
any adjustments, disassembly or
any kind of repair .
DISCONNECT SPARK PLUG WIRE
BEFORE SERVICING UNIT.
WARNING: TO AVOID PERSONAL INJURY, ALWAYS
TURN MACHINE OFF, MAKE SURE ALL MOVING
PARTS COME TO A COMPLETE STOP.
1. Wait for engine to cool and disconnect spark plug.
2. Drain fuel and oil from the engine.
3. Remove bag, bag tray, quick release, upper handle and clutch
cable from upper handle. Do not kink, stretch, or break control
cables, control housings, or end fittings while removing handles.
4. Remove chain guard, chains and jackshaft assembly (see page 9,
Drive Chain).
5. Remove housing top plate by removing bolts around outside of
housing.
6. Leaving engine fastened to top plate, remove impeller bolt and
lock washer and slide impeller off crankshaft ( A puller may be
required).
7. Retain shim washers used at end of crankshaft for use at impeller
reinstallation (see fig. 7). However, your unit may or may not have
required the use of shim washers.
8. If impeller slides off freely, proceed to (step 11 or step 15).
(Do not drop impeller).
9. If impeller does not slide off crankshaft, place two crowbars
between impeller and housing on opposite sides. Pry impeller away
from engine until it loosens.
Using a penetrating oil can help loosen a
stuck impeller.
10. If the impeller cannot be loosened, obtain a 1” (25.4mm) longer
bolt of the same diameter and thread type as the impeller bolt. Invert
engine and impeller and support engine above ground to prevent
recoil damage. Thread longer bolt by hand into the crankshaft until
bolt bottoms. Using a suitable gear or wheel puller against the bolt
head and the impeller back-plate (near the blades), remove impeller
from shaft.
IMPELLER REMOVAL
RECONNECT SPARK PLUG WIRE,
GUARDS, BAG, CAPS AND / OR
HOSE BEFORE STARTING ENGINE.
ENGINE: See engine manufacturer
operator's instructions.
DEBRIS BAG: See page 6.
17.117.1
17.117.1
17.1
17.117.1
17.117.1
17.1
IMPELLER REMOVAL and CHIPPER ADJUSTMENT
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