Technical Information · issue 47 of 1997
Carburetor; HD filter base; HD filter cover; crank
Model 044, 046 Chainsaws ± Series 1128
IssueTI 47/1997
Engine family 1128
Part changes (3)
| Was | Becomes | What the bulletin says |
|---|---|---|
| 1128 121 5602 | 1128 121 5603 | In addition, the semi-fixed jet E2F=NNOU=NON=RSMO=ETMF=in the HD-16 carburetor for model 046 will be replaced by the new version 1128 121 5603 (68). |
| 0000 400 1303 | 0000 400 1305 | 046:=qhe original ignition module E1F=MMMM=QMM=NPMP=Ewith 3-arm yoke and timing adjustment) will be replaced by the new universal ignition module E2F=MMMM=QMM=NPMR=Ewith 2-arm yoke, without timing adjustment). |
| 0000 400 1300 | 0000 400 1305 | 132TI021 SC 0000 400 1300 will be replaced by the new version MMMM=QMM=NPMR=E2F. |
Full text
Page 1 of 11
Technical Information
47.97
Model 044, 046 Chainsaws ± Series 1128
&RQWHQWV
1. Carburetor (sealed adjusting screws, modified valve jet and semi-fixed jet, new limiter caps)
2. Filter base 044 / grommet (different shape for carburetors with limiter caps, new setting symbols)
3. Filter cover 046 (new setting symbols, neutral replacement filter cover)
4. Engine
- Ball bearings (cover washers deleted)
- Crankcase 044 (modified muffler mounting)
- Muffler (smaller exhaust opening, gasket between casings)
- 044 heat shield (new - improved heat dissipation)
5. Ignition system
- 044 flywheel (higher air throughput)
- Ignition module (new universal ignition module, 046 with 2-arm yoke, without timing adjustment)
6. Front hand guard (new rubber mount)
7. 044 versions available
- 044 Flush cut handlebar model (0.5 mm cylinder gasket)
- 044 Arctic with carburetor heating (modified filter configuration)
Compliance with EPA regulations =see TI 27.97= is achieved with the modifications =except 4.2, 5.2
and 6.1= described below. The factory applies the label shown below to all machines that conform to
the latest standard.
Andreas Stihl IMPORTANT ENGINE INFORMATION
ENGINE FAMILY: A8XS. R ; Type: ; DISPL.: CC;M.D.:
THIS ENGINE CONFORMS TO U.S. EPA PHASE 1 EMISSION REGULATIONS
000TI013 KN
FOR ULGE´s. REFER TO OWNER´S MANUAL FOR MAINTENANCE
SPECIFICATIONS AND ADJUSTMENT. 967 34
)47.97 - 2
1.=Carburetor
The original carburetors will be replaced by the fol-
lowing new versions:
044:=eaJNT=ENNOU=NOM=MSOOF=in place of
HD-10B (1128 120 0619)
046:=eaJNS=ENNOU=NOM=MSOPF=in place of
HD-8A (1128 120 0610)
The original valve jet E1F=NNOU=NON=RQMP=will be re-
placed by the new valve jet 1128 121 5404 to opti-
mize running behavior at part load and reduce fuel
consumption.
In addition, the semi-fixed jet E2F=NNOU=NON=RSMO
(70) in the HD-16 carburetor for model 046 will be
replaced by the new version 1128 121 5603 (68).
O-rings are fitted on the two adjusting screws of
139TI015 KN
the new carburetors to provide a more effective
seal against the ingress of secondary air. 1 2
Limiter caps are fitted on the high speed and the
low speed screws of the EPA carburetors to
restrict the range of adjustment. The adjusting
screws have knurled heads to accept the caps.
The limiter caps are pushed on to the heads of
the adjusting screws and held in position by the
knurling. Once installed, the caps are flush with
the insert (bottom of dome).
1.1=New carburetor parts / function
1===`~ps
- limit range of adjustment 6
of H and L screws
2===eigh speed screw
- head knurled to hold cap in position 5
3===iow speed screw 4
- head knurled to hold cap in position
4===lJrings
3
- to seal against carburetor body
1
5===fnserts with mounting bores
139TI011 KN
- molded stops in the bores restrict
adjustment travel of limiter caps 2
)47.97 - 3
1.2 Service note
The following replacement carburetors should be
used for older machines (without EPA equipment):
044:=eaJNR=ENNOU=NOM=MSORF=in place of
HD-10B (1128 120 0619)
046:=eaJNQ=ENNOU=NOM=MSOQF=in place of
HD-8A (1128 120 0610)
With the exception of the limiter caps and adjusting
screws, these carburetors are technically the same
as versions HD-16 and HD-17.
If the limiter caps are removed from
EPA-approved machines in the course of a
repair, new caps have to be fitted after
completing the repair and adjusting the
carburetor as specified.
1.3=Standard setting
The machine comes from the factory with the opti-
mum carburetor setting and the limiter caps fitted
on the adjusting screws. This setting is exactly the
same as the standard setting described in chapter H L
"Adjusting Carburetor" in the owner’s manual
(H=3/4; L=1/4 open - starting from the
lean stop in each case). 270° 270°
Corrections are possible only within a range of
270 degrees because the integrally molded stops
132TI022 KN
(arrows) in the bores restrict further movement of
the limiter caps.
This enables the mixture to made leaner for
operation at high altitudes, if necessary, and helps
prevent the mixture being enriched beyond EPA
emission limits.
Correction of carburetor setting for higher
DOWLWXGHV
If the engine runs unsatisfactorily, slight
readjustment may be necessary:
• Check standard setting
• Warm up the engine
• Turn the high speed adjusting screw (H) and
low speed adjusting screw (L) clockwise
(leaner)
> =ff you make the setting too lean, the
maximum permissible engine speed will be
exceeded - risk of engine damage.
)47.97 - 4
1.4=Repair / servicing / basic setting
The limiter caps have to be removed to replace the
adjusting screws or clean the carburetor. Use pul-
ler 5910 890 4500=for this purpose.
• Rotate limiter caps (adjusting screws)
counterclockwise as far as stop.
• Screw puller into cap counterclockwise until
cap comes off the adjusting screw.
139TI013 KN
> Do not reuse the limiter caps.
1.4.1 Basic setting Ewithout caps)
After fitting the adjusting screws, carry out the
basic setting:
• Starting with screws against their seats:
+ = Open 1 full turn
L Z=lpen 1 full turn
1.4.2=Fitting limiter caps
> =^lw~ys=fit=new=limiter=c~psK
• Insert the limiter caps in the bores as shown in
====the=illustr~tion=J=check correct position of===============N
OXJV - see arrows.
• Push the caps on to the adjusting screws until
they are flush with the insert (1).
The position of the limiter caps (and the adjusting
132TI023 KN
screws) is exactly the same as the standard
setting (see 1.2). LA
1.4.3=Adjusting idle speed
• Set engine speed to 2,500 rpm with the idle
speed screw /$ .
> =rse a tachometer.
1.5=Fuel =mix ratio
EPA approval was obtained with a fuel/oil mix ratio of 50:1. No emission measurements are
available for other mix ratios. See also TI 27.97.
1.6=Federal Emission Control Systems Utility Engines ± see TI 27.97.
)47.97 - 5
1.7=Summary
Item Part Name Original New Rem.
version version
044
1 Carburetor HD-10B 1128 120 0619 --- 1)
including items 9, 10, 12, 14
2 Carburetor HD-15 --- 1128 120 0625 3)
including items 9, 10, 12, 14, 15
3 Carburetor HD-17 EPA --- 1128 120 0622
including items 9, 11, 13 to 16
046
4 Carburetor HD-8A 1128 120 0610 --- 1)
including items 7, 9, 10, 12
5 Carburetor HD-14 --- 1128 120 0624 3)
including items 7, 9, 10, 12, 14, 15
6 Carburetor HD-16 EPA --- 1128 120 0623
including items 8, 9, 11, 13 to 16
7 Fixed jet 70 1128 121 5602 --- 2)
8 Fixed jet 68 --- 1128 121 5603
9
============044 and 046
Valve jet
1128 121 5403 1128 121 5404 2)
10 Low speed screw 4116 122 6800 1128 122 6803 2)
11 Low speed screw EPA --- 1128 122 6804
12 High speed screw 1127 122 6700 1127 122 6701 2)
13 High speed screw EPA --- 1128 122 6703
14 Spring (2x) 4116 122 3001 1128 122 3003 2)
15 Sealing ring (2x) --- -*-
16 Cap (2x) --- 4203 121 2700
All other parts as before
Modification to be introduced: from start of production of EPA version
5HPDUNV
1) Original version of part no longer available from factory
2) Original version of part remains available as spare
3) see 1.2
-*- Part not available as separate item
2.= Grommet / filter base 044
A new JURPPHW 1128 123 7502 has been develo-
ped for the carburetor equipped with limiter caps. It
fits into the recess for the limiter caps (see arrow)
and is then flush with the limiter caps.
H
139TI016 KN
LA
)47.97 - 6
The filter base=for the 044 with HD filter has been
modified (arrow) so that the grommet can be remo-
ved and fitted without having to remove the filter
base.
A filter base with a different carburetor setting sym-
bol (H=3/4, L=1/4) will installed as standard.
Replacement filter bases will be supplied without
132TI016 SC
setting symbols in future and can therefore be
used for both the original and new versions of the
machine. 1 2
1 = Original filter base
2 = New filter base
3. =Filter cover 046
A filter cover with a different carburetor setting
symbol (H=3/4, L=1/4) will be installed as standard.
Replacement filter covers will be supplied without
setting symbols in future and can therefore be
used for both the original and new versions of the
machine. fo
6XPPDU\
Item Part Name Original New Rem.
version version
1 Grommet 1128 123 7500 1128 123 7502 1)
2 Filter base (044) 1128 124 3408 1128 124 3408 2)
3 Filter cover (046) 1128 140 1001 1128 140 1001 3)
Modification to be introduced: from start of production of EPA version
5HPDUNV
1) Original version of part remains available as spare
2) Only modified version of part is available from factory
3) Unmodified version of part will be supplied until existing factory stocks are exhausted
4.=Engine
4.1=Crankcase =044
The tapped mounting bosses for the muffler have
been raised 1.0 mm (thickness of heat shield) and
extended to the rear to allow longer screws
(M6x20) to be used to secure the muffler.
The modified crankcase has been given a new
part number (see Summary).
132TI017 KN
)47.97 - 7
The heat shield and two M6x20 screws will be
included with the crankcase for a transitional
period.
Service note:=ff a modified crankcase is installed
in an older machine, it is essential to fit the heat
shield 1128 141 3201 as well to compensate for
the higher mounting bosses (see 4.3) – use M6x20
screws.
4.2=Ball bearings
Ball bearings that are open on both sides will again
be installed instead of bearings with a shield
washer.
The part number of the bearing at the ignition side
changes from 9503 003 6555 to 9503 003 0340.
The part numbers for the bearing at the clutch side
remain unchanged.
4.3=Muffler
The size of the exhaust opening in the lower ca-
sing has been reduced from 18 mm to 10.5 mm on
the 044=~nd from 18 mm to 9.5 mm on the 046.
a
Modified mufflers have been allocated new part
numbers (see Summary).
A new gasket 1128 149 0500 is fitted between the
muffler casings to achieve an effective seal.
132TI018 KN
044 only:=jSx20 screws are used to mount the
new mufflers (with heat shield) to the new
crankcase (with extended tapped bosses).
Service note
The new mufflers (with smaller exhaust opening)
may only be used for machines with EPA
approval. The original mufflers (with 18 mm
exhaust opening) should still be used in older
machines.
4.4=Heat shield =044
A new heat shield 1128 141 3201 is installed be-
tween the cylinder and muffler to protect the cylin-
der and crankcase from heat radiated from
the muffler.
This change was necessary because of the higher
132TI019 SC
temperature caused by the smaller exhaust
opening in the muffler.
)47.97 - 8
4.5 Summary
Item Part Name Original New Rem.
version version
1 Crankcase (044); 1128 020 2112 1128 020 2117 1)
2 Crankcase (046) 1128 020 2116 1128 020 2116 2)
each of above includes items 3:
3 Ball bearings 6202 9503 003 6555 9503 003 0340 1)
4 Muffler (044) 1128 140 0607 1128 140 0604 3)
5 Muffler (046) 1128 140 0616 1128 140 0609 3)
6 Gasket --- 1128 149 0500
7 Heat shield (044) --- 1128 141 3201
8 Pan head screw M6x18 (044) 9022 341 1310 ---
9 Pan head screw M6x20 (044) --- 9022 341 1300
Modification to be introduced: from start of production of EPA version
5HPDUNV
1) Original version of part will be supplied from factory only as long as existing stocks last
2) Unmodified version of part will be supplied until existing factory stocks are exhausted
3) Original version of part remains available for machines without EPA approval
5.=Ignition system
5.1=Flywheel =044
The geometry of the flywheel has been changed to
further enhance engine cooling. Air throughput has
been increased by reducing the number of blades
from 28 to 21 and optimizing the blade contour.
It has been possible to reduce the size of the
magnets and counterweight by using a new
magnet material (rare earth). Furthermore, this
permits an increase in the effective blade surface
area and also reduces the flywheel’s weight.
132TI020 KN
The modified flywheels have been given new part 1 2
numbers (see Summary).
1 = Original flywheel
2 = New flywheel
Service note
The original and new versions of the flywheel are
fully interchangeable.
)47.97 -
5.2=Ignition module
046:=qhe original ignition module E1F=MMMM=QMM
1303 (with 3-arm yoke and timing adjustment) will
be replaced by the new universal ignition
module E2F=MMMM=QMM=NPMR=Ewith 2-arm yoke,
without timing adjustment).
044:=qhe original universal ignition module
132TI021 SC
0000 400 1300 will be replaced by the new version
MMMM=QMM=NPMR=E2FK=======================================================N=======================O
5.3=Summary
Item Part Name Original New Rem.
version version
1 Ignition module 044 (2-arm) 0000 400 1300 0000 400 1305 1)
2 Ignition module 046 (3-arm) 0000 400 1303 --- 1)
3 Ignition module 046 (2-arm) --- fo 0000 400 1305
4 Flywheel 044 (standard) 1128 400 1200 1128 400 1214 1)
5 Flywheel 044 (heating) 1128 400 1213 1128 400 1215 1)
Modification to be introduced: in progress, flywheel beginning of 1998
5HPDUNV
1) Original version of part will be supplied from factory only as long as existing stocks last
6.=Front hand guard
The original hand guards on all versions will be
replaced by new hand guards. The new hand
guards are supported in a rubber bushing at the
fan side and secured with an M5x35 screw.
4 1
Service note========================================================P
2
The new hand guards (complete with both
bushings and screw) and the original versions are
fully interchangeable.
Before installing, push the brass bushing E2F=into
the rubber bushing E3FK=qhen fit both bushings
(flange of brass bushing pointing inwards) in the
hand guard E1F=~nd secure the hand guard in
145TI021 KN
position with the M5x35 screw E4F.
)47.97 - 10
6XPPDU\
Item Part Name Original New Rem.
version version
1 Hand guard, 044 1128 790 9100 1128 790 9150 1)
1.1 Hand guard, 046 1128 790 9102 1128 790 9152 1)
each of above includes items 2 to 4:
2 Bushing --- 1124 792 5500
3 Bushing --- 1124 792 5505
4 Spline screw IS M5x35 --- 9022 341 1080
5 Screw and washer assembly 0000 790 6103 --- 2)
Modification to be introduced in progress
5HPDUNV
1) Original version of part will be supplied from factory only as long as existing stocks last
2) Original version of part remains available as spare for other models
7.=044 versions available
7.1=Flush cut handlebar model
It is no longer necessary from a technical point of
view to use the 1.0 mm cylinder gasket on this
version.
The 1.0 mm thick cylinder gasket, will be change
to a 0.5 mm thick gasket. Ans is the same gasket
as the wrap-around handle version of 044.
7.2=044 Arctic =with carburetor heating
In connection with the EPA modifications, this
version will be supplied with the "HD filter
configuration" in future. Only difference: The winter
filter element will be used in place of the HD filter
cartridge.
Note: ft is possible to use the HD filter cartridge
during the mild weather season (temperatures
above freezing).
)47.97 - 11
7.3=Summary
Item Part Name Original New Rem.
version version
6.1
1 Cylinder gasket 1.0 mm 1128 029 2302 --- 1)
2 Cylinder gasket 0.5 mm --- 1128 029 2301
6.2 044 Arctic
3 Carburetor box cover 1128 140 1905 --- 1)
4 Air filter (front half) 1128 120 1610 --- 1)
5 Baffle 1128 120 4100 --- 1)
6 Air filter (rear half) 1128 120 1625 --- 1)
7 Filter cover --- 1128 140 1003
8 Air filter (winter) --- 0000 120 1651
9 Flange --- 1128 120 2201
10 Locknut VM5 --- 9216 263 0700
11 Filter base --- 1128 124 3408
Modification to be introduced: from start of production of EPA version
5HPDUNV
1) Part remains available as spare for other versions fo
Last Technical Information on models 044, 046: 09.97
1997 Andreas Stihl Andreas Stihl - D1/MTK
Technical Documentation 6192 Page 2 of 11
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