17MAINTENANCE
Use only a qualified mechanic for any adjustments, disassembly or any kind of repair .
WARNING: TO AVOID PERSONAL INJURY, ALWAYS TURN MACHINE OFF, MAKE SURE ALL MOVING PARTS COME TO A COMPLETE STOP.
DISCONNECT SPARK PLUG WIRE
BEFORE SERVICING UNIT.
ENGINE: See engine manufacturer operator's instructions.
DEBRIS BAG: See page 6.
RECONNECT SPARK PLUG WIRE,
GUARDS, BAG, CAPS AND / OR
HOSE BEFORE STARTING ENGINE.
17.1IMPELLER REMOVAL and CHIPPER ADJUSTMENT
CHIPPER BLADE REMOVAL AND SHARPENING
Chipper blades are normal replaceable wear items.
DANGER Chipper blade is sharp.
Replace any damaged blade.
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.
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.
IMPELLER REMOVAL
1.Wait for engine to cool and disconnect spark plug.
2. Drain fuel and oil from the engine.
3.Remove bag, quick release, and upper handle. Do not kink, stretch, or break control cables, control housings, or end fittings while removing handles.
4. Self propelled units only.
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
CORRECTINCORRECT
Blade | Blade |
40o
EDGE OF CHIP
RELIEF HOLE
Fig. 5
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.
Part No. 890313 | Page 8 of 12 | Form No. F010396D |
