HEDGE TRIMMER
Workshop Manual
February 2010
USA models: CHTZ2401/ 2460 and HTZ2401/ 2460
EU models: CHTZ6000/ 7500, HTZ7500 and eHT602D/ 752S
China models: HTZ7510, CHTZ6010 and eHT603D/ 753S
Instruction
This workshop manual describes the main maintenance items and procedures for the
Husqvarna Zenoah hedge trimmer.
This manual is classified into two categories; one includes important notices concerning
disassembly and reassembly including "Cautions for disassembly" and "Cautions for
reassembly", the other includes inspection and adjustment items such as "Carburetor
adjustment". After each item is thoroughly understood, apply the understanding to the actual
maintenance tasks.
Frequently asked questions are also included in this manual. However, many cases need rich
maintenance experience and informed judgment. Please refer to this manual for maintenance
support.
NOTES
1. The contents of this manual are based on specifications as of February 2010.
The contents may be modified due to performance improvement or some other reason
without notice.
2. Use Zenoah brand-name parts when replacing a part during maintenance, etc.
The manufacturer does not bear any responsibility if trouble occurs during parts use of other
than brand-name parts.
3. Read this manual thoroughly before beginning the maintenance work, understand it, apply
the content to the actual maintenance tasks and guide the customer if directions, are
needed.
Contents
1. Engine Specifications
.................................................................................................... 2
2. Engine Construction/ Maintenance Specifications...................................
3
3. Engine Special Tools...................................................................................
7
4. Engine Service Guide
4-1 Clutch Shoe Removal ................................................................................................... 8
4-2 Rotor Removal .............................................................................................................. 9
4-3 Module Assembly ........................................................................................................ 10
4-4 Piston Pin Removal ..................................................................................................... 10
4-5 Clutch Assembly (GZ23) ............................................................................................. 11
4-6 Muffler Gasket Installation (G20LH).............................................................................. 11
4-7 Throttle Wire Adjustment .............................................................................................. 11
4-8 Piston Inserting Direction ............................................................................................ 12
4-9 Piston Pin Snap Ring Assembly ................................................................................ 12
4-10 Engine Short Block Assembly ................................................................................... 13
4-11 Insulator Assembly .................................................................................................... 14
4-12 Connecting of Fuel Pipes............................................................................................ 14
5. Carburetor Specifications
........................................................................................ 15
6. Carburetor Construction/ Maintenance Specifications
................................. 16
7. Carburetor Service Guide
7-1 Recommended Tools.................................................................................................... 17
7-2 Carburetor Conforms to Exhaust Emissions Regulations ........................................... 17
7-3 Limiter Cap Removal/ Installation ............................................................................... 18
7-4 Idling Speed Adjustment ............................................................................................. 18
7-5 Carburetor Inspection .................................................................................................. 19
7-6 Carburetor Adjustment ................................................................................................ 21
8. Unit Specifications
........................................................................................................ 24
9. Unit Construction/ Maintenance Specifications
............................................... 25
10. Unit Special Tools....................................................................................
26
11. Unit Service Guide
11-1 Engine Removal ........................................................................................................ 26
11-2 Cutting Blade Assembly Removal ............................................................................. 27
11-3 Clutch Drum Replacement ........................................................................................ 27
11-4 Grease Supply to Gear Case .................................................................................... 28
2
1. Engine Specifications
Item Specifications
Sales Region
(Reference)
USA model EU model China model
Hedge Trimmer Model
CHTZ
2401
2460
HTZ
2401
2460
CHTZ6000
※1
CHTZ7500
※2
HTZ7500
※3
eHT602D
※1
eHT752S
※2
HTZ7510
※1
CHTZ6010
※2
eHT603D
※1
eHT753S
※2
Engine Model GZ23N GZ23N G20LH GZ23N G20LH
Displacement
cm
3
23.6 ←
←←
← 21.7 23.6 21.7
Cylinder
Bore×Stroke
mm
(in)
34×26
(1.34×1.02)
←
←←
←
32×27
(1.26×1.06)
34×26
(1.34×1.02)
32×27
(1.26×1.06)
Carburetor (Walbro) WYA-67 WYA-39 WYL-225A WYA-72A WYL-190B
Ignition System CDI
Spark Plug NGK CMR7H ←
←←
← NGK BPMR7A NGK CMR7H CHAMPION CJ6Y
Stopping Method Primary coil short-circuiting
Air Cleaner Dry type
Clutch Type Centrifugal clutch (Sintered metal clutch shoe)
Dry Weight
(without
attachment)
kg
(lb)
5.67
(12.5)
5.58
(12.3)
5.9 (13.0)
※1
6.1 (13.4)
※2
5.8 (12.8)
※3
4.7 (10.4)
5.8 (12.8)
※1
5.9 (13.0)
※2
4.7 (10.4)
Fuel Tank Capacity
15.9 fl. oz (US)
(470 cc)
470 cc 400 cc 470 cc 400 cc
Operating Speed
rpm
6,000～10,000 ←
←←
← ←
←←
← ←
←←
← ←
←←
←
Idling Speed
rpm
3,000 ←
←←
← ←
←←
← ←
←←
← ←
←←
←
Clutch
Engagement
Speed
rpm
4,000 3,800 4,000 3,800
No-Load
Maximum Speed
(with attachment)
rpm
10,500 11,000 10,500 11,500 10,500
Max. HP
kw / rpm
(PS/ rpm)
0.85/ 8,000
(1.15/ 8,000)
0.80 / 8,000
※1, 2
(1.09/ 8,000)
0.74/ 8,000
※3
(1.00/ 7,500)
0.64/ 7,000
※1
(0.88/ 7,000)
0.71/ 7,000
※2
(0.96/ 7,000)
0.74/ 8,000
(1.00/ 7,500)
0.55/ 7,000
※1
(0.75/ 7,000)
0.62/ 7,000
※2
(0.84/ 7,000)
Max.
Torque
N･m/ rpm
(kgf･m/ rpm)
1.10/ 6,000
(0.11/ 6,000)
1.23/ 6,000
※1, 2
(0.13/ 6,000)
1.00/ 7,000
※3
(0.10/ 7,000)
1.05/ 5,000
※1
(0.11/ 5,000)
1.10/ 5,000
※2
(0.11/ 5,000)
1.00/ 7,000
(0.10/ 7,000)
0.86/ 5,500
※1
(0.09/ 5,500)
0.90/ 6,000
※2
(0.09/ 6,000)
Fuel
Mixture (Gasoline 50: Oil 1)
When using Husqvarna Zenoah genuine oil
3
2. Engine Construction/
Maintenance Specifications
GZ23N Engine (1/2)
Crankcase
Bolt M5x L16 T27 (3)
2.94～
～～
～5.88 N・
・・
・m
(30～
～～
～60 kgf・
・・
・cm)
Cap Assy.
Packing (2)
Tank
Filter
Collar
Pipe Comp.
Muffler
Gasket
Bolt M5x L50 T27 (3)
6.86～
～～
～10.78 N・
・・
・m
(70～
～～
～110 kgf・
・・
・cm)
TARGET: 8.82 N・
・・
・m (90 kgf・
・・
・cm)
Tighten the bolts again after
operation inspection.
Bolt M4x L10 T27 (4)
0.98～
～～
～0.96 N・
・・
・m
(10～
～～
～20 kgf・
・・
・cm)
TARGET: 1.47 N・
・・
・m (15 kgf・
・・
・cm)
Cover (2)
Gasket (2)
Cylinder
Gasket
Insulator
Bolt M5x L20 T27 (4)
4.90～
～～
～6.90 N・
・・
・m
(50～
～～
～70 kgf・
・・
・cm)
TARGET: 5.88 N・
・・
・m (60 kgf・
・・
・cm)
Bolt M5x L50 T27 (2)
2.94～
～～
～5.88 N・
・・
・m
(30～
～～
～60 kgf・
・・
・cm)
TARGET: 3.92 N・
・・
・m (40 kgf・
・・
・cm)
Knob
0.49～
～～
～0.98 N・
・・
・m
(5～
～～
～10 kgf・
・・
・cm)
Cover
Element
Plate
Screw
Choke Plate
Packing
Lever
Gasket
Body
Carburetor Assy.
Clip
4
2. Engine Construction/
Maintenance Specifications
Spacer (2)
Spark Plug, NGK CMR7H
9.80～
～～
～13.72 N・
・・
・m
(100～
～～
～140 kgf・
・・
・cm)
Bolt M5x L22 T27 (4)
5.88～
～～
～7.84 N・
・・
・m
(60～
～～
～80 kgf・
・・
・cm)
TARGET: 6.86 N・
・・
・m (70 kgf・
・・
・cm)
Cylinder
Base Gasket
Piston Rings
Piston
Piston Pin
Snap Ring (2)
Bearing
Washer (2)
Bearing
Crankcase
Deflector
Bolt
Oil Seal
Washer
Clutch Spring
Clutch Shoe (2)
Wave Washer (2)
Screw M6x L22 (2)
4.90～
～～
～7.8 N・
・・
・m
(50～
～～
～80 kgf・
・・
・cm)
Clutch Plate
15.68～
～～
～21.56 N・
・・
・m
(160～
～～
～220 kgf・
・・
・cm)
Left hand thread
Bolt M5x L10 T27 (2)
2.94～
～～
～5.88 N・
・・
・m
(30～
～～
～60 kgf・
・・
・cm)
Plate
Crankshaft Comp.
Key
Gasket, case
Crankcase
Bearing
Spring
Tube
Cord Comp.
Coil
Engine Cover
Cap
Grommet
Bolt M5x L16 T27 (2)
2.94～
～～
～5.88 N・
・・
・m
(30～
～～
～60 kgf・
・・
・cm)
Bolt M4x L16 T27 (2)
2.45～
～～
～3.92 N・
・・
・m
(25～
～～
～40 kgf・
・・
・cm)
Bolt M5x L16 T27 (4)
2.94～
～～
～5.88 N・
・・
・m
(30～
～～
～60 kgf・
・・
・cm)
Nut M8x P1.0
9.80～
～～
～14.68 N・
・・
・m
(100～
～～
～150 kgf・
・・
・cm)
Recoil Assy.
Bolt M5x L20 (3)
4.90～
～～
～7.84 N・
・・
・m
(50～
～～
～80 kgf・
・・
・cm)
Rotor Assy.
Oil Seal
Ring
１
１１
１
２
２２
２
３
３３
３
４
４４
４
４
４４
４
GZ23N Engine (2/2)
Service Ability Limit
No. Maintenance items Standard
Limit
１
１１
１
Cylinder bore φ34 (1.339)
Peel off of plating or
expose of base metal.
２
２２
２
Piston diameter
φ33.98 (1.3378)
φ33.86 (1.3331)
３
３３
３
Connecting rod
small end bore
φ11 (0.433)
φ11.05 (0.435)
４
４４
４
Crankshaft diameter
at main bearing
(MAG, PTO)
φ12 (0.4724) φ11.97 (0.4713)
Unit: mm (in)
5
2. Engine Construction/
Maintenance Specifications
G20LH Engine (1/2)
Knob
0.48～
～～
～0.98 N・
・・
・m
(5～
～～
～10 kgf・
・・
・cm)
Cover
Element
Screw 4x L12
Choke Plate
Lever
Carburetor Assy.
Gasket
Sleeve (2)
Screw M5x L55 (2)
2.94～
～～
～4.41 N・
・・
・m
(30～
～～
～45 kgf・
・・
・cm)
Screw TP M4x L16 (2)
1.96～
～～
～2.94 N・
・・
・m
(20～
～～
～30 kgf・
・・
・cm)
Rear Cover
Muffler Cover
Screw M4x L12
1.47～
～～
～1.96 N・
・・
・m
(15～
～～
～20 kgf・
・・
・cm)
Screw TP M4x L16
1.96～
～～
～2.94 N・
・・
・m
(20～
～～
～30 kgf・
・・
・cm)
Cli
p
Pi
p
e Com
p
.
Cli
p
Filter
Cushion
Tank
Ca
p
Ass
y
.
Absorber (2)
Screw M5x L16
2.45～
～～
～3.43 N・
・・
・m
(25～
～～
～35 kgf・
・・
・cm)
Front Cover
Bolt M5x L16 (4)
2.94～
～～
～4.41 N・
・・
・m
(30～
～～
～45 kgf・
・・
・cm)
Bolt M6x L12 (2)
4.90～
～～
～7.84 N・
・・
・m
(50～
～～
～80 kgf・
・・
・cm)
Pulley Assy.
Spring
Ratchet
Recoil
Screw TP M4x L16 (4)
1.96～
～～
～2.94 N・
・・
・m
(20～
～～
～30 kgf・
・・
・cm)
China Model
Cover
Filter
Screen
Plate
Housin
g
Gasket
Filte
r
Sleeve (2)
Lever
Washer
Screw (2) M5x L60
6
2. Engine Construction/
Maintenance Specifications
Spark Plug, NGK BPMR7A
14.7～
～～
～21.6 N・
・・
・m
(150～
～～
～220 kgf・
・・
・cm)
Cap
Spring
Cap
Nut
Adjust Screw
Bolt M5x L22 (2)
5.88～
～～
～7.84 N・
・・
・m
(60～
～～
～80 kgf・
・・
・cm)
Cylinder
Screw M5x L16 (2)
2.94～
～～
～4.41 N・
・・
・m
(30～
～～
～45 kgf・
・・
・cm)
Muffler
Gasket
Insulator
Gasket
Gasket
Bolt M5x L50 (4)
6.86～
～～
～9.80 N・
・・
・m
(70～
～～
～100 kgf・
・・
・cm)
TARGET: 8.82 N・
・・
・m (90 kgf・
・・
・cm)
Clutch Boss
7.68～
～～
～11.8 N・
・・
・m
(80～
～～
～120 kgf・
・・
・cm)
Clutch
Spring (2)
Clutch
Shoe
(
2
)
Crankcase
Pin
Case
Gasket
Oil Seal
Bearing
Crankshaft
Comp.
Bearing
Ring
Oil Seal
Snap Ring (2)
Piston Pin
Washer (2)
Bearing
Piston
Piston Ring
Crankcase
Rotor
Coil
Spacer (2)
Cord Comp.
Bolt M4x L20 (2)
2.45～
～～
～3.92 N・
・・
・m
(25～
～～
～40 kgf・
・・
・cm)
Nut M8x P1.0
7.68～
～～
～11.8 N・
・・
・m
(80～
～～
～120 kgf・
・・
・cm)
Bolt M5x L20 (3)
3.92～
～～
～6.86 N・
・・
・m
(40～
～～
～70 kgf・
・・
・cm)
１
１１
１
２
２２
２
３
３３
３
４
４４
４
４
４４
４
G20LH Engine (2/2)
Service Ability Limit
No. Maintenance items Standard Limit
１
１１
１
Cylinder bore φ32 (1.260)
Peel off of plating or
expose of base metal.
２
２２
２
Piston diameter
φ31.98 (1.2591)
φ31.86 (1.2543)
３
３３
３
Connecting rod
small end bore
φ11 (0.433) φ11.05 (0.435)
４
４４
４
Crankshaft diameter
at main bearing
(MAG, PTO)
φ10 (0.3937) φ9.97 (0.3925)
Unit: mm (in)
7
3. Engine Special Tools
Model
Part Name
Part No.
(RedMax P/N)
External Appearance Usage
GZ23N G20LH
Hex Wrench
3304-97611
(520 956 10-01)
For socket screw of
Hex.3mm, 4mm, and
5mm.
Torx Wrench
2670-96410
(516 97 42-01)
For socket screw of
Torx T20, T25, and T27.
Puller Assy
2890-96100
(520 76 93-01)
To remove rotor.
Piston Stopper
4810-96220
(521 34 51-01)
To hold crankshaft when
disassembling /
assembling clutch shoe
and rotor.
Piston Stopper
2670-96220
(516 84 93-01)
To hold crankshaft when
disassembling /
assembling clutch shoe
and rotor.
Air Gap Gauge
3350-96240
(521 06 82-01)
To set ignition coil.
Rod Assy
1101-96220
(516 18 29-01)
To remove / install piston
pin.
Wrench
2841-96110
(516 95 87-01)
To remove / install clutch
shoe.
8
4. Engine Service Guide
4-1 Clutch Shoe Removal
1. Remove the spark plug, and set the piston stopper
into the plug hole.
GZ23N Piston stopper: 4810-96220 (521 34 51-01)
G20LH Piston stopper: 2670-96220 (516 89 93-01)
2. Remove the clutch shoes.
GZ23N:
Remove clutch shoe mounting bolts, then remove
the clutch shoes.
G20LH:
Remove the clutch shoe with the wrench
(2841-96110/ 516 95 87-01).
3. GZ23N: If necessary, remove the clutch plate with
the puller assembly (2890-96100/ 520 76 93-01)
by turning it counterclockwise.
Mounting Bolt (HEX 14mm)
14mm
Clutch Shoe
Piston Stopper
(
4810-96220/ 521 34 51-01
)
GZ23N
G20LH
GZ23N
14mm
Clutch Shoe
Wrench
(2841-96110/
516 95 87-01)
Piston Stopper
(2670-96220/
516 89 93-01)
Puller Assy.
(
2890-96100/ 520 76 93-01
)
17mm
Puller Bolts
(8mm)
Clutch Plate
9
4. Engine Service Guide
4-2 Rotor Removal
1. Remove the recoil assembly and engine cover.
2. Remove the spark plug, and set the piston stopper
into the plug hole.
3. Remove the rotor from the crankshaft.
GZ23N:
-1. Loosen the rotor nut.
-2. Hold the rotor in your hand and place the
aluminum block on the rotor nut.
-3. Tap the aluminum block with a hummer, then
remove the rotor.
G20LH:
-1. Remove the rotor nut.
-2. Remove the rotor with the puller assembly.
/(2890-96100/ 520 76 93-01)
-3. Apply 8mm puller bolts.
GZ23N
Rotor
Rotor Nut (M8)
Rotor
Hummer
Aluminum Block
G20LH
17mm
Rotor Nut (M8)
Rotor
Puller Assy.
(
2890-96100/ 520 76 93-01
)
Puller Bolts
(8mm)
10
4. Engine Service Guide
4-3 Module Assembly
Insert a gauge (3350-96240/ 521 06 82-01) between
the rotor magnet metal and module. Tighten the bolts
while pushing the module against the rotor.
NOTE: Apply Lock Tight (Medium strength type:
Threebond 1342, LOCTITE 242 or equivalent to) to
the bolts.
Torque: 2.45～3.92N・m (25～40kgf・cm)
Module Resistance
Primary Side
( Iron Core Primary Lead )
Secondary Side
( Iron Core High Tension Lead )
Air Gap
76ｋΩ±8ｋΩ 2ｋΩ±0.2ｋΩ
0.4～0.5mm
(0.016～0.02in)
The resistance values shown above are the reference values for resistance tester
measurement. A resistance value is within the normal range shows no internal leakage
or any other defect.
We supply the measurement equipment (gap tester) that can measure spark energy
while the engine is running.
4-4 Piston Pin Removal
1. Remove the snap rings from both sides of the
piston pin.
2. Engage the rod assy (1101-96220/ 516 18 29-01)
to the piston pin and gently tap with a plastic
hammer to push out the pin.
3699-90247
(521 23 09-01)
Three-point
gap tester
* Connect
Negative
Side (black)
to Iron Core.
Reference
Hard hammering may damage the big end of
the connecting rod.
Caution:
Piston
Rod Assy.
(1101-96220/ 516 18 29-01)
Plastic
Hummer
Rotor
Module
Hex Wrench
(3304-97611/
520 956 10-01)
Air Gap Gauge
(3350-96240/ 521 06 82-01)
11
4. Engine Service Guide
4-5 Clutch Assembly (GZ23N)
Before installing the clutch, apply the molybdenum
grease into the mounting holes of he clutch shoe, and
make sure that the arrow mark on the shoe is to the
clutch plate side.
NOTE:
・
・・
・
Do not apply the grease to the clutch lining.
・
・・
・
Take care when positioning the direction of the
wave washer.
The type of the wave washer used in this unit
depends on the model. Pay attention to use the
correct type. If a washer of different size is used,
excessive gear noise will result.
4-6 Muffler Gasket Installation (G20LH)
Heat resisted liquid gasket application to the muffler
gasket.
Liquid gasket: ThreeBond “#1207C”
4-7 Throttle Wire Adjustment
Adjust the throttle lever to the position at the lowest
velocity, and pull the wire sleeve lightly. The normal
play of the throttle wire is 1 or 2mm (0.039 or 0.078in).
If it is too large or too small, loosen the lock nut, and
reposition the wire receive on the carburetor side.
Clockwise: Play becomes large.
Counterclockwise: Play becomes small.
Reference
1.35mm (0.053in)
Thickness： 0.5mm (0.020in)
Color: Black
GZ23N
G20LH
Muffler
Muffler Gasket
Apply liquid gasket.
Wire Sleeve
Throttle
Wire
Lock Nut
Wire Retaining Nut
1～2mm (0.039～0.078in)
Retaining
Screw
1～2mm
(0.039～0.078in)
EU models
Apply
grease.
Clutch Shoe
Clutch Shoe
A
rrow Mark
Clutch Spring
Wave Washer
Mounting Screw
4.90～7.8 N・m
(50～80 kgf・cm)
Clutch Drum side
Clutch Plate
side
12
4. Engine Service Guide
4-8 Piston Inserting Direction
Make sure to point the recessed mark (arrow or
triangle) on the piston head to the exhaust (muffler)
side.
4-9 Piston Pin Snap Ring Assembly
Fit the snap ring in the groove firmly and position the
end gap of the snap ring opposite the notch.
After the snap ring is installed, check that it fits firmly
in the correct direction.
Turn the snap ring using thin tipped tool and check
that it moves smoothly in its groove.
If the snap ring is improperly installed, it will not move
smoothly in its groove.
Reference
If the snap ring is poorly inserted or the end gap
of the snap ring is incorrectly positioned, the
snap ring may comes off during engine operation
resulting in damage to the engine.
Never reuse a snap ring. Always insert a new one.
Caution:
A
rrow Mark
Piston
[Exhaust Side]
Notch
End Gap
Snap Ring
Piston Pin
Groove
Snap Ring
Snap Ring
13
4. Engine Service Guide
4-10 Engine Short Block Assembly
Reassemble the engine in the reverse order of removal, and note these items.
● Apply 2T oil to the main bearing, smaller-end (needle) bearing, piston, inside of the cylinder, the space
between the weight and the bearing. Degrease the outer surface of the bearing and crank case ID at
bearing area.
● Apply grease to the lip area of the oil seal, and degrease the outer surfaces of the oil seal.
2T: 2-cycle Engine Oil
Degrease.
MAG side
Snap Ring
Piston Pin
Thrust
Washer
Thrust
Washer
Needle Bearing
Snap Ring
Snap Ring
Cylinder
: Inside
: Between the weight
and the bearing.
PTO side
Main Bearing
: ID
Base Gasket
Case Gasket
Crank Case
Crank Case
Main Bearing
: ID
Degrease.
Degrease.
Degrease.
Piston
: Outer surface
: Lip area
Oil Seal
: Lip area
Oil Seal
14
4. Engine Service Guide
4-11 Insulator Assembly
Match the elongate hole of the insulator to the pulse
hole of the cylinder.
4-12 Connecting of Fuel Pipes
When connecting the fuel pipes, connect the suction
pipe (black) and return pipe (clear) properly.
Elongate
Hole
Insulator
Pulse
Hole
Cylinder
Gasket
Carburetor
Return Pipe
(Clear)
Suction Pipe
(Black)
15
5. Carburetor Specifications
Item Specifications
Sales Region USA model EU model China model
Hedge Trimmer
Model
CHTZ2401/ 2406
HTZ2401/ 2406
CHTZ6000
CHTZ7500
HTZ7500
eHT602D
eHT725S
HTZ7510
CHTZ601
eHT753
eHT603
Engine Type GZ23N GZ23N G20LH GZ23N G20LH
Type Name WYA-67 WYA-39 WYL-225A WYA-72A WYL-190B
Part Number
848F0G8101
(511 35 42-01*)
848F018102 848E0J8101 848F0D8100 848E0A8102
Specifications [mm (in)]
Main Jet 2-1/8±1/2 # 33 # 36 # 33 # 39
Metering lever
height
1.5±0.16
(0.059±0.0063)
← ←
←
←
Lead Air:
φ8.0 (0.315)
Lead Air:
φ7.0 (0.276)
Lead Air:
φ7.0 (0.276)
Venturi Bore
Mixture Air:
φ9.0 (0.354)
Mixture Air:
φ9.0 (0.354)
φ9.0 (0.354)
Mixture Air:
φ9.0 (0.354)
φ9.0 (0.354)
Choke Bore φ13.2(0.520) φ13.2 (0.520) φ12.0 (0.472) φ13.2 (0.520) φ12.0 (0.472)
Standard Engine Speed [rpm]
Idling 3,000
←
←
←
←
Clutch engaging 4,000 3,800 4,000 3,800
←
Stall 5,600
←
←
←
5,000
Operating Speed 6,000～10,000
←
←
←
←
No-Load
Maximum Speed
10,500 11,000 10,500 11,500 10,500
ID Peak Engine
Speed
4,500±10 3,800±10 3,400±10 3,800±10 3,700±10
ID Rich Down 1,400～1,600 700～900 300～500 700～900 600～800
Set ID 3,000±100 3,000±100 3,000±100 3,000±100 3,000±100
Full Throttle 9,000～10,700 11,000
←
←
←
Adjustment Angle for Engine Start (Loosen then tighten)
Throttle Valve Adjust
Screw
6-1/2 7-1/2 7-1/2 7-1/2 10-1/2
L-needle Adjustment
Angle
10-1/2 12-1/2 10-1/2 13-1/2
1 (CCW)
Tighten then
loosen
( *): RedMax P/N
16
6. Carburetor Construction/
Maintenance Specifications
G20LH
GZ23N
Main Jet #33
H-Needle
Washer
Swivel
Throttle Valve
Assembly
Ring
Carburetor Body
O-Ring
Gasket
Pump Diaphragm
Screen
Body Assembly
Inlet Valve
Spring
Metering
Lever
Pin
Screw
Gasket
Main Diaphragm
Body
Pump
Pump Cover
Screw
USA model only
Throttle Valve
Assembly
Swivel
Carburetor Body
O-Ring
Main Jet #36 or #39
Gasket
Pump Diaphragm
Screen
Body Assembly
Inlet Valve
Pin
Screw
Gasket
Main Diaphragm
Body
Pump
Screw
Pump Cover
Ring
Spring
Metering
Lever
17
7. Carburetor Service Guide
7-1 Recommended Tools
We also supply the carburetor maintenance tools as shown below. Please purchase them if needed.
No. Tool Number (RedMax P/N) Description
3699-90211 (521 23 08-01) Pressure Gauge
3699-90537 (514 44 60-01) Tachometer PET-1000
7-2 Carburetor Conforms to Exhaust Emissions Regulations (USA, EU model only)
The carburetor flow rates of all Husqvarna Zenoah engine blowers are individually pre-adjusted to pass
exhaust emissions regulations.
A limiter cap is installed in the idling limiter to prevent an operator carelessly changing the idle setting resulting
in non-conformance with exhaust emission regulations.
Execute a correct adjustment according to page 21 "7-6 Carburetor Adjustment".
A limiter cap closes the L-needle adjustment hole of
the throttle valve.
Carburetor adjustments with caps removed must be conducted by Emission Certified Servicing
Dealers ONLY.
The dealer must supply the unit to the customer in original configuration, using the manufacturer’s
carburetor adjustment procedure, which includes having the limiter caps in place before the unit is
put into service.
Knowingly removing or rendering inoperative any device, element, or design installed on or in a
non-road engine which is in compliance with E. P. A. or C. A. R. B. (USA), STAGE (EU) regulations
is classified as TAMPERING.
TAMPERING is a violation of FEDERAL LOW, resulting in significant civil penalties (fines) of up to
$25,000 for each violation.
ATTENTION!!! IMPORTANT!!!
L-needle
Limiter Cap
Throttle Valve
18
7. Carburetor Service Guide
7-3 Limiter Cap Removal/ Installation
Tool
The limiter cap tool (carburetor maintenance tool:
848-8W9-0080/ 521 53 38-01) is used for limiter cap
installation/removal.
Removal
Insert the limiter cap tool extraction tool's threading
(M2 counterclockwise threading) into the idling
limiter's hole and screw it counterclockwise while
giving pressure.
When it is firmly threaded, pull the limiter cap.
Installation
Insert a new limiter cap in the low speed mixture
needle hole. Press the cap deeply into low speed
mixture needle hole to prevent tampering.
7-4 Idling Speed Adjustment
Slow and Middle Speeds
Adjust the fuel supply under idling conditions by turning the idling limiter.
1. Remove the limiter cap.
2. Turn the screw with a commercially available screw
driver (tip width: 2.5mm).
Clockwise (CW):
Fuel mixture becomes lean. (Speed increases.)
Counterclockwise (CCW):
Fuel mixture becomes rich. (Speed decreases.)
Limiter cap insertion side
Limiter cap tool extraction side
Screw unit
(M2 counterclockwise threading)
Limiter Cap Tool
If it is difficult to screw in the limiter cap tool,
firmly press the tool while screwing. When
threads are completely meshed, pull it out in
one stroke. If cap is damaged and stays in the
hole, use a pick type tool to remove it.
Caution:
Be sure to install only a new limiter cap.
The limiter cap is a very small part. Pay
attention not to lose it.
Caution:
After completion of the adjustment, be sure to
install the limiter cap.
Caution:
Without Limiter Cap
Limiter Cap
Limiter cap tool extraction side
Press it while turning it
counterclockwise.
Pull it out.
Limiter cap is removed.
Limiter cap insertion side
Limiter cap
(new part)
With Limiter Cap
Screw Driver
Increases
Decreases
Decreases Increases
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
Page is loading ...
/
