Chain saw
Workshop Manual
April 2009
Instruction
This maintenance manual gives special explanation to maintenance standards, procedures,
and the main causes of malfunction.
This manual also includes many common customer inquiry items. Please make use of this
manual for maintenance work and supplement this manual by your rich the experience and
judgment you already possess.
“WARNING”
1. The contents of this manual are based on specifications as of January 2009.
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
Strato-charged Engine
1. Outline ............................................................................................................... 1
2. Operating Principle ............................................................................................. 2
Construction
1. Engine Short Block Parts ................................................................................... 3
2. Recoil and Clutch Parts ...................................................................................... 4
3. Right Handle and Carburetor Parts .................................................................... 5
4. Chain Brake Parts .............................................................................................. 6
Specifications and Technical Data
.................................................................... 7
Service Guide
1. Teardown
1-1 Carburetor Removal .................................................................................... 8
1-2 Recoil Assy. Removal .................................................................................. 9
1-3 Handle Comp. Removal .............................................................................. 9
1-4 Spark Plug Removal .................................................................................. 10
1-5 Rotor Removal .......................................................................................... 10
1-6 Module Removal ....................................................................................... 10
1-7 Clutch Removal ......................................................................................... 11
1-8 Oil Pump Removal .................................................................................... 11
1-9 Inlet Pipe Removal .................................................................................... 12
1-10 Muffler Removal ...................................................................................... 12
1-11 Engine Short Block Removal ................................................................... 13
1-12 Crank Shaft Removal .............................................................................. 14
2 Reassembly
2-1 Engine Short Block Assembly .................................................................... 15
2-2 Heat-resistant Gasket Assembly ............................................................... 16
2-3 Inlet Pipe Assembly ................................................................................... 16
2-4 Worm Gear Assembly ............................................................................... 17
2-5 Clutch Assembly ........................................................................................ 17
2-6 Rotor Assembly ......................................................................................... 17
2-7 Module Assembly ...................................................................................... 18
2-8 Handle Comp. Assembly ........................................................................... 18
2-9 Switch Cord and Earth Cord Wiring ........................................................... 19
2-10 Carburetor Assembly ............................................................................... 20
2-11 Fan Cover Assembly ............................................................................... 20
Carburetor
1. Specifications
1-1 Carburetor Specifications .......................................................................... 21
1-2 Recommended Tools ................................................................................. 21
1-3 Construction .............................................................................................. 22
1-4 Carburetor Conforms to Exhaust Emissions Regulations .......................... 23
2. Carburetor Adjustment
2-1 Required Tools and Parts .......................................................................... 24
2-2 Pre Adjustment Check List ........................................................................ 24
2-3 Adjustment ................................................................................................ 24
1
Strato-charged Engine
1. Outline
Unlike the conventional 2-cycle engine scavenging system, the Strato-charged Engine
(
※
1)
scavenges burnt
gas by the stratified lead air scavenging method.
By creating a stratified air layer between burnt gas and the air-fuel mixture, this system significantly reduces
exhaust of unburned air-fuel mixture.
(※1)
Strato is a coined word derived from “stratified” (e.g. stratified layer of air / gas), and ”stratosphere”, which
conjures up the image of purity and calm.
Air Valve
Carburetor
Throttle Valve
Inlet pipe
Manifold
Cleaner element
Piston
Lead Air
Air-fuel Mixture
2
Strato-charged Engine
2. Operating Principle
1. As the piston proceeds through the upstroke of the
intake cycle, the crankcase vacuum sucks the lead
air in through the scavenging port via the groove on
the piston skirt.
2. As the piston begins its down stroke after top dead
center, a scavenging port starts to open and lead
air in the scavenging port moves into the cylinder
earlier than the air-fuel mixture.
3. As the piston begins its to upstroke after bottom
dead center, burnt gas in the cylinder is pushed out
through the exhaust port by lead air. Therefore,
almost no air-fuel mixture is emitted.
Carburetor
Lead Air
Scavenging Port
Grooved Piston
Air-fuel Mixture
Burnt Gas
Exhaust Port
Air-fuel Mixture
Air-fuel Mixture
Lead Air
Exhaust Port
Burnt Gas
Air-fuel Mixture
Lead Air
3
Construction
1. Engine Short Block Parts
Screw TP5x 19L
(Precoat thread lock screw)
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Chain Catcher
Under Guard
Muffler
Gasket
Spark Arrester
Muffler Guide
Engine Case
Nut M5 (2)
Torque: 5.9～
～～
～7.8 N・
・・
・m
(0.6～
～～
～0.8 kgf・
・・
・m)
Cylinder
Piston Ring
Bolt
Snap Ring
Piston
Thrust Washer
Piston Pin
Needle Bearing
Crankshaft Comp.
Main Bearing
Oil Seal
Snap Ring
Oil Seal
Bumper
Screw M4x 10L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Apply thread lock: #1342
Exhaust Pipe
Top Cover
Bolt M5x 14L (3)
Torque: 4.9～
～～
～7.8 N・
・・
・m
(0.5～
～～
～0.8 kgf・
・・
・m)
Bolt M5x 14L (2)
Torque: 4.9～
～～
～7.8 N・
・・
・m
(0.5～
～～
～0.8 kgf・
・・
・m)
Bolt M4x 10L (4)
Torque: 1.5～
～～
～2.5 N・
・・
・m
(0.15～
～～
～0.25 kgf・
・・
・m)
Bolt M5x 20L (4)
Torque: 6.9～
～～
～8.8 N・
・・
・m
(0.7～
～～
～0.9kgf・
・・
・m)
Gasket
TR, Cover TPO
Apply liquid gasket: #1217F
TR, Cover MAG
Apply liquid gasket: #1217F
Crank Case
Bolt M5x 20L
Torque: 4.9～
～～
～7.8 N・
・・
・m
(0.5～
～～
～0.8 kgf・
・・
・m)
Screw TP5x 19L
(Precoat thread lock screw)
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Bolt M4x 10L (4)
Torque: 1.5～
～～
～2.5 N・
・・
・m
(0.15～
～～
～0.25 kgf・
・・
・m)
Bolt M5x 14L
Torque: 4.9～
～～
～7.8 N・
・・
・m
(0.5～
～～
～0.8 kgf・
・・
・m)
EU: Option
4
Construction
2. Recoil and Clutch Parts
Thrust Washer
Oil Pipe (suction side)
Oil Pump
Bolt M4x 14L (2)
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Pump Cover
Worm Gear
Needle Bearing
Plate
Bolt M5x 14L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Apply thread lock:
Threebond #1322 or
Loctite #262
Oil Pipe
(discharge side)
Clutch Drum
Clutch 13mm
Torque: Three Tightening Step
27.4→
→→
→19.6→
→→
→23.5 N・
・・
・m
(2.8→
→→
→2.0→
→→
→2.4 kgf・
・・
・m)
Clutch Spring
Label, Recoil
Screw TP5x 19L (4)
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Rope
Knob
Spiral Spring
Reel
Spring
Screw
Fan Cover
DF Guide
Nut M8
Torque: 14.7～
～～
～18.6 N・
・・
・m
(1.5～
～～
～1.9 kgf・
・・
・m)
Rotor Assy.
Bolt M4x 20L (2)
Torque: 2.9～
～～
～4.9 N・
・・
・m
(0.3～
～～
～0.5 kgf・
・・
・m)
Apply thread lock:
Threebond #1342 or
Loctite #242
Ratchet Pulley
Terminal
Coil Comp.
Spring
Plug Cap
Spacer
Screw TP5x 19L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Plug Cover
Sparkplug M10 (CMR7H)
Torque: 8.8～
～～
～12.8 N・
・・
・m
(0.9～
～～
～1.3 kgf・
・・
・m)
Starter Case
5
Construction
3. Right Handle and Carburetor Parts
Left Handle
Oil Tank Cap
Gasket
Air Pipe
Gasket
Fuel Tank Cap
Elbow
Label, Caution
Front Spring
Screw TP5x 19L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Screw M5x 20L
Torque: 4.9～
～～
～7.8 N・
・・
・m
(0.5～
～～
～0.8 kgf・
・・
・m)
Stopper Bolt TP5.4x 16L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
PTO Spring
Air Cleaner Cover
Knob
Air Cleaner Element
Seal
Carburetor Guide
Seal
Carburetor
Seal
Bolt M5x 45 (2)
Torque: 3.4±
±±
±0.2 M・
・・
・m
(0.35±
±±
±0.02 kgf・
・・
・m)
Apply thread lock:
Threebond #1342 or
Loctite #242
Manifold
Fuel Pipe
Fuel Filter
Grommet
Grommet
Breather
Primer Pump
Knob Bracket
V
alve
Seal
Spring
Throttle Lever
Throttle Rod
Safety Lever
Switch Cord
Earth Cord
Grip Cover
Screw TP5x 19L (2)
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Switch
Pipe
Pipe
Joint
Oil Filter Pipe
Joint
Pipe
Oil Filter
Damper Spring
Band
Handle Comp.
Screw TP5x 19L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Screw TP5x 19L
Torque: 2.0～
～～
～2.9 N・
・・
・m
(0.2～
～～
～0.3 kgf・
・・
・m)
Hook
(USA)
Screw TP5x 20L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Screw TP5x 19L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Inlet Pipe
Bolt M5x 12L (2)
Torque: 5.9～
～～
～7.8 N・
・・
・m
(0.6～
～～
～0.8 kgf・
・・
・m)
Apply thread lock:
Threebond #1342 or
Loctite #242
Screw TP5x 19L
Torque: 2.5～
～～
～3.9 N・
・・
・m
(0.25～
～～
～0.4 kgf・
・・
・m)
Plate, Hook
Hook
(EU)
6
Construction
4. Chain Brake Parts
Spring Cover
Brake Band
Brake Spring
Chain Cover
Nut
Tensioning Screw
Tensioning Gear
Outer Plate
Slide Arm
Roller
Label, Cover
Spring
Tensioning Nut
Spring
Roller
Washer
Spring
Spacer
Screw
Inertia Weight
Nut
Torque: 1.9～
～～
～2.9 N・
・・
・m
(0.2～
～～
～0.3 kgf・
・・
・m)
Brake Lever
Spacer
Front Handle Guard
Screw TP4x 12L (2)
Torque: 0.7～
～～
～1.5 N・
・・
・m
(0.07～
～～
～0.15 kgf・
・・
・m)
Screw TP4x 12L (2)
Torque: 0.7～
～～
～1.5 N・
・・
・m
(0.07～
～～
～0.15 kgf・
・・
・m)
Stud Bolt
Inner Plate
Bolt M5x 12L
Torque: 4.9～
～～
～7.8 N・
・・
・m
(0.5～
～～
～0.8 kgf・
・・
・m)
7
Specifications and Technical Data
Item Unit Specifications
Model T GZ3500T
Engine type Air cooled 2-stroke single cylinder piston valve gasoline engine
Cylinder bore×stroke mm (in.) φ40×28 (1.58×1.10)
Displacement Cm
3
35.2
Effective compression ratio 7.4
Fuel Fuel-oil mixture Mixing ratio
・ Zenoah genuine 2-cycle oil 50: 1
・ 2-cycle oil available on market 25: 1
Type Diaphragm type butterfly throttle valve
Carburetor
Model Walbro WT-935
Starting method Recoil starter
Engine lubrication Fuel-oil mixture
Ignition system CDI with automatic timing advance system
Spark plug NGK CMR7H
Stopping method Primary coil short-circuiting
Cooling system Forced air cooling
Air cleaner Dry type
Output axle rotation direction Clockwise (View from output axle)
Clutch type Centrifugal clutch (Sintered metal clutch shoe)
Chain oil Zenoah genuine chain oil or Engine oil SAE #10-30
Lubricating method Automatic lubrication
Oil pump type Mechanical oil pump with discharge adjustment
Type Sprocket nose bar
Guide bar
Length mm (in.) 300 (12) 350 (14)
Saw chain 91VG Links 45 52
Anti-vibration mechanism Three-points mount
Throttle type With safety lock
Chain brake Auto activation band type
Safety guard With left-hand guard
Overall dimensions
(Length×Width×Height)
mm (in.) 290×235×230 (11.4×9.25×9.06)
Dry weight (Power unit only) kg (lb) 3.3 (7.3)
Fuel tank capacity cm
3
245
Oil tank capacity cm
3
170
Operating speed rpm 7000～12500
Idling speed range rpm 2900 ±200
Clutch engaging speed range rpm 4200 ±300
Full load fuel consumption L/ h/ rpm 0.95/ 9000
Chain oil discharge level cm
3
/ min 3～9 Variable/ 8000
Maximum output kW (PS)/ rpm 1.45 (1.97)/ 9000
Maximum torque N･m (kgf･m)/ rpm 1.57 (0.16)/ 6500
8
Service Guide
1. Teardown
●
●●
● Empty the fuel tank before starting the work to prevent leaking of composite fuel (if any).
●
●●
● Empty the oil tank before starting the work to prevent leaking of chain oil (if any) from the
tank.
Remove the chain cover, the guide bar, the saw chain, and the air cleaner cover from the engine body.
1-1 Carburetor Removal
1. Remove the mounting Bolts, hold the body of the
cleaner element and remove the manifold and the
cleaner element.
Make sure the seal remains attached to the cleaner
element.
2. Remove the other carburetor mounting screw.
Do not try to demount the carburetor yet.
If you try, the throttle rod will be bent.
3. Remove the mounting screws of the right handle
and lift up the grip cover.
4. Lift up the carburetor, and pull out the fuel hose.
5. Pull out the throttle rod from the throttle lever, and
remove the carburetor.
The carburetor guide comes off and be
careful not to lose it.
CAUTION
CAUTION
CAUTION
Mounting Screw (2)
TP5x 19L (T27)
Grip Cover
Throttle Rod
Carburetor
Carburetor
Guide
Throttle Lever
Fuel Hose
Mounting Bolt (2)
M5x 45L (T27)
Carburetor
Mounting Screw
TP5x 20L (T27)
Seal
Manifold
Cleaner element
9
Service Guide
1-2 Recoil Assy. Removal
1. Remove the mounting screws of the recoil assy.
and demount the recoil assy.
2. Remove the fan cover.
The DF guide comes off and be careful not to
lose it.
1-3 Handle Comp. Removal
1. Pull and remove the switch cord and the earth cord by hand.
2. Remove the mounting bolts of the front spring and PTO spring.
3. Remove the Inlet pipe and the air pipe from the handle comp.
For easy removal, push the right handle with your weight. The pipe rises and can be easily removed.
4. Pull out the oil pipe, and separation the engine case and the handle comp.
CAUTION
Mounting Screw (4)
TP5x 19L (T27)
Fan Cover
DF Guide
Recoil Assy.
Mounting Screw
M5x 20L (T27)
Mounting Screw
TP5x 16L (T27)
1.
PTO Spring
Switch Code
Earth Code
Front Spring
Push the right handle with your weight.
Oil Pipe
Handle Comp.
Inlet Pipe
(Mixture Side)
Inlet Pipe
(Lead Air Side)
Air Pipe
2.
2.
3.
4.
Engine Case
10
Service Guide
1-4 Spark Plug Removal
1. Remove the mounting screw, then remove the plug
cover.
2. Remove the plug cap, then remove the spark plug.
3. Set the stopper (special tool: 4810-96220) into the
plug hole.
1-5 Rotor Removal
Remove the mounting nut using the box spanner, then
remove the rotor.
1-6 Module Removal
Remove the mounting bolts, then remove the module.
Mounting Nut
M8 (12 mm)
Box Spanner
(12mm)
Rotor
Mounting Bolt (2)
M4x 20L (T27)
Spacer
Terminal
Module
Mounting Screw
TP5x 19L (T27)
Spark Plug
(M10)
Plug Cap
Stopper
Plug Cover
11
Service Guide
1-7 Clutch Removal
Remove the clutch using the box spanner, and remove the plate, clutch drum and the needle bearing.
1-8 Oil Pump Removal
1. Remove the worm gear and the washer.
2. Remove the mounting bolt, then remove the pump cover.
3. Remove the mounting bolts, and disconnect the oil pipe then remove the oil pump.
4. Remove the mounting bolt, then remove the inner plate.
Clutch
(counterclockwise threading)
Box Spanner
(13mm)
Plate
Needle Bearing
Clutch Drum
Mounting Bolt
M5x 14L (T27)
Mounting Bolt (2)
M4x 14L (T27)
Mounting Bolt
M5x 12L (T27)
Oil Pump
Pump Cover
Washer
Inner Plate
Worm Gear
Oil Pipe (discharge side)
12
Service Guide
1-9 Inlet Pipe Removal
Remove the mounting bolts, then remove the inlet
pipe.
1-10 Muffler Removal
1. Remove the mounting screw, then remove the
chain catcher.
The catcher and the under guard are tightened
together.
2. Slide the under guard and remove it from the
casing.
3. Remove the mounting bolts and the mounting nuts
using the box spanner, then remove the muffler.
The engine casing contains a heat-resistant
gasket. You need not remove it, but if it
comes off, be sure to remount it.
CAUTION
Mounting Bolt (2)
M5x 12L (T27)
Inlet Pipe
Mounting Screw
TP5x 19L (T27)
Under Guard
Chain Catcher
Mounting Nut
M5 (8 mm)
Mounting Bolt (2)
M5x 14L (T27)
Box Spanner
(8mm)
Muffler
Heat-resistant Gasket
13
Service Guide
1-11 Engine Short Block Removal
1. PTO side:
Remove the mounting bolts and the screw.
2. MAG side:
Remove the mounting bolts, and pull up the top
cover from the engine case.
3. Detach the short block from the engine case.
Mounting Bolt (2)
M5x 14L (T27)
Mounting Screw
TP5x 19L (T27)
PTO side
Mounting Bolt (2)
M5x 14L (T27)
Top Cover
MAG side
Engine Short Block
Engine Case
Heat-Resistant Gasket
14
Service Guide
1-12 Crank Shaft Removal
1. Remove the mounting bolts, then remove the crank
case.
2. Pull out the piston from the cylinder, and separate
the oil seals and snap ring.
If necessary, remove the main bearings.
3. Remove the snap rings and pull out the piston pin,
then remove the piston.
If necessary, remove the thrust washers and the
needle bearing from the connecting rod.
Mounting Bolt (4)
M5x 20L (T27)
Cylinder
Crank Case
Main Bearing
Oil Seal
Piston
Cylinder
Oil Seal
Snap Ring
Piston
Snap Ring
Piston Pin
Thrust Washer
Needle Bearing
Crank Shaft
Thrust Washer
Snap Ring
Connecting Rod
15
Service Guide
2 Reassembly
Reassemble the chain saw in the reverse order of teardown, and note these items.
2-1 Engine Short Block Assembly
● 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 surface of the bearing and crank case ID at bearing area ( area).
● Make sure to point the recessed mark (arrow) on
the piston head to the exhaust (muffler) side.
● Fit the snap ring in the groove firmly and position
the end gap of the snap ring 90 degree the notch.
・
・・
・ 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.
● Apply grease to the lip area of the oil seal.
Degrease surfaces of the oil seal.
CAUTION
CAUTION
Piston
OK NG
Snap Ring Direction
Arrow Mark
Exhaust Side
End Gap
Bolt (4) M5x 20L (T27)
Torque: 6.9～
～～
～8.8 N・
・・
・m
(0.7～
～～
～0.9kgf・
・・
・m)
MAG side
Crank Case
Snap Ring
Oil Seal
Piston
Piston Pin
Thrust Washer
Thrust Washer
Oil Seal
Needle Bearing
Snap Ring
Snap Ring
Cylinder
: Inside
: Between the weight
and the bearing
PTO side
Main Bearing
: ID
Main Bearing
2T: 2-cycle Engine Oil
: ID
16
Service Guide
● Apply liquid gasket to the crank case.
Liquid Gasket: Threebond #1217F
● Match the end surface of the oil seal with the end
surface of the crank casing (to prevent interference
with the main bearing) when reassembling the oil
seal in the MAG side.
・
・・
・ Be careful not to move the oil seal too
much. If done, the oil seal may interfere with
the rotor.
・
・・
・ Degrease the shaft if it has any grease on it.
(Otherwise, the rotor may be broken.)
2-2 Heat-resistant Gasket Assembly
Remount the heat-resistant gasket prior to the muffler.
For easy remounting, first set the engine side of the
gasket, bend the opposite side, and then set.
2-3 Inlet Pipe Assembly
Apply liquid gasket to the suction side of cylinder.
Liquid Gasket: Threebond #1217F
Do not apply liquid gasket to areas near the
pulse hole.
If done, the pulse hole may be choked.
CAUTION
CAUTION
Heat-resistant Gasket
Oil Seal
Match the end surface of the
oil seal with the end surface
of the crank casing.
Gap
Bearing
MAG side
Do not apply liquid gasket to
areas near the pulse hole.
17
Service Guide
2-4 Worm Gear Assembly
Apply grease to the worm gear and the shaft.
2-5 Clutch Assembly
● Direct the chamfering portion of the plate to the
engine side.
● Apply loads to the clutch in the order of 27.4, 19.6,
and 23.5 N.m in three stages (to prevent
loosening).
Degrease the screw portion of the shaft to
prevent over-tightening.
2-6 Rotor Assembly
Fit the key of the magnet to the keyway of the crank
shaft when re-assembling the magnet.
Degrease screw portions and the tapered
portion of the shaft.
CAUTION
CAUTION
Rotor
Crank Shaft
Key
Keyway
27.4 N・
・・
・m
(2.79 kgf・
・・
・m)
Clutch
19.6 N
・
・・
・
m
(2.00 kgf・
・・
・m)
23.5 N・
・・
・m
(2.40 kgf・
・・
・m)
Plate
Chamfering
portion
Engine Side
Washer
Crank Shaft
Worm Gear
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