Technical Information · issue 39 of 1997
026: Carburetor with fixed jet instead of high spe
Model 026 Chainsaws - Series 1121
IssueTI 39/1997
Engine family 1121
Part changes (1)
| Was | Becomes | What the bulletin says |
|---|---|---|
| 1118 123 7500 | 1121 123 7500 | The original grommet 1118 123 7500 will be replaced by grommet 1121 123 7500. |
Full text
Page 1 of 2
Technical Information
39.97
Model 026 Chainsaws - Series 1121
&RQWHQWV
1. Carburetor with fixed jet instead of high speed
screw (WT 493 and WT 403 A)
2. Grommet (no hole for H screw)
3. Carburetor box cover (pictogram showing setting)
4. Summary
The following changes are being made to meet
EPA regulations =see TI 27.97
1. Carburetor
The WT 426 carburetor (with H, L and LA screws)
previously installed in saws with and without
compensator will be deleted from machine number
2 36 988 352K=ft will be replaced by new
carburetors (without high speed screw, with
different fixed jets):
- Type WT 403 A for 026 PRO with compensator
- Type WT 493 for 026 without compensator
1.1=Fixed jet
The fixed jet in the new carburetors replaces the
high speed screw and provides the proper fuel mix-
ture during full-load operation.
Maximum engine RPM is preset by the fixed jet
and cannot be altered.
The fixed jet is screwed into the bottom of the
metering chamber and is easily removed and
installed for cleaning.
Note:=^=fixed jet with a smaller bore is installed
133TI032 KN
in the WT 493 carburetor (only 026 without
compensator) to make up for the flow resistance
of the fleece filter.
1
1 Fixed jet
1.2=Adjustment
Low speed screw (L) and idle screw (LA) are set
in the normal way.
Standard setting: L = 1 (see owner’s manual)
)39.97 - 2
2.=Grommet
The original grommet 1118 123 7500 will be
replaced by grommet 1121 123 7500. The new
grommet has only one hole for the L screw.
It is colored gray for easy identification. 1 2
3.=Carburetor box cover
133TI034 KN
The pictogram has been changed.
It now refers only to the low speed screw (L).
Replacement carburetor box covers are
supplied without pictogram
The part numbers remain unchanged. 1 = Grommet 1118 123 7500
2 = Grommet 1121 123 7500
4.=Summary
Item Part Name Original New Rem.
version fo version
1 Carburetor WT 426 1121 120 0650 --- 1)
2 Carburetor WT 403 A (026 PRO) --- 1121 120 0610
including items 3, 4, 8 to 14:
3 End cover 1121 121 0810 1121 121 0810
4 Fixed jet 0.56 (026 PRO) --- 1120 121 5600
5 Carburetor WT 493 --- 1121 120 0613
including items 6 to 14:
6 End cover 1113 121 0800 1113 121 0800
7 Fixed jet 0.54 --- 1130 121 5400
8 Throttle shutter 1121 121 3301 1123 121 3301 1)
9 Check valve --- 4133 120 8600
10 Valve jet 1121 121 5400 1115 121 5401 1)
11 Sealing ring 4130 122 3600 4124 122 3600 1)
12 Washer 4130 121 8601 1111 121 8605 1)
13 Low speed screw 1121 122 6802 1121 122 6803 1)
14 Throttle shutter 1121 121 3301 1123 121 3301 1)
15 Grommet 1118 123 7500 1121 123 7500 1)
All other carburetor parts as before (see parts list)
Modification to be introduced from machine number 2 36 988 352
5HPDUNV
1) Original version of part remains available for older machines
Last Technical Information on models 024, 026: 18.97 (on EPA: 27.97)
1997 Andreas Stihl Andreas Stihl - D1/MTK-sc
Technical Documentation 6137 Page 2 of 2
Extracted from the manufacturer's 2012 service catalogue. Most of these PDFs embed fonts with a shifted character map, so the text above was recovered rather than copied — read it as a faithful but imperfect transcription, and treat the page image above each block as the authority where the two disagree — the figures exist only there, because they are vector drawings that text extraction cannot keep.