Technical Information · issue 42 of 1994
023 C: New version with quick chain tensioner
Model 023 Chain Saws - Series 1123
IssueTI 42/1994
Engine family 1123
Full text
Page 1 of 4
Technical Information
42.94
Model 023 Chain Saws - Series 1123
New 023 C version with quick chain tensioner and easy start system
A new version of the 023 is the first chain saw
in the world to be equipped with a quick chain
tensioner. It also features the STIHL easy start
system.
The quick chain tensioner:
● is operated by hand -
● it permits simple and fast adjustment of chain
tension and convenient clamping of the guide
bar without the need for tools -
● greatly simplifies maintenance work on the
cutting attachment -
● is a completely new feature in the world of
chain saws. Page 2 of 4
Technical Information 42.94 - Page 2
STIHL’s patented quick chain tensioner can be The new version has been designated the "023 C".
backfitted to any model 021, 023 or 025 chain As in other models, the suffix "C" in the sales
saw. designation indicates that the chain saw is
equipped with a convenience feature, i.e. the
The STIHL easy start system helps reduce quick chain tensioner in this case.
physical effort during starting and thus enhances
operator comfort. The system was described
in detail in TI 10.94.
1. Description of operation
1.1 Conventional chain tensioner
Chain tension is first adjusted as required and
then guide bar is then clamped in that position
with the mounting nuts.
Tools are necessary (screwdriver, combination
wrench) for both these operations.
1.2 Quick chain tensioner
2 1
3
5
135TI001 Page 3 of 4
Technical Information 42.94 - Page 3
Turning the adjusting wheel (1) also turns the
tensioning gear (2). The tensioning gear converts
the rotational movement of the adjusting wheel
into a
linear movement of the guide bar. Depending on
the direction of rotation, the guide bar moves eit-
her forwards or backwards to tension or slacken
the chain as required.
The wingnut (3) engages the collar stud and
clamps the guide bar. It is only tightened by hand.
Anti-rotation lock
The wingnut (3) can be turned only when its hinged
wing (4) is folded out. In the closed condition, the
wing’s teeth engage the teeth in the chain sprocket
cover and prevent it working loose.
2. New parts and major modifications to
existing parts
2.1 Collar stud
On machines with a quick chain tensioner the
fo 1
cutting attachment is clamped in position by the
front collar stud (1) only. 2
The rear collar screw (2) only serves to prevent
rotational movement of the guide bar. For this
reason only the 5 mm (0.2") head of the screw
projects from the engine housing.
135TI002
2.2 Chain sprocket cover
The adjusting wheel, wingnut and teeth of the anti-
rotation lock have been integrated in the chain
sprocket cover (see Figure on page 2).
2.3 Spiked bumper
The spikes of the spiked bumper are now longer
to compensate for the forward projecting chain
sprocket cover.
135TI011
Left: Spiked bumper 1123 664 0500
Right: Version 1123 664 0501 for
quick chain tensioner Page 4 of 4
Technical Information 42.94 - Page 4
2.4 Quick chain tensioner mounting kit
All existing model 021, 023, and 025 chain saws
can be retrofitted with the quick chain tensioner
mounting kit 1123 007 1008.
After the quick chain tensioner is fitted the
integrally molded spiked bumper (on 021 and 023)
or the original spiked bumper 1123 664 0500
(on 025) will no longer have sufficient reach to
make contact with the wood.
For safety reasons the spiked bumper
1123 664 0501 included in the kit must
be fitted.
This spiked bumper has longer spikes and offers
good saw support in the cut.
Detailed fitting and use instructions are supplied
with the kit.
3. New spare parts
Part Name Part No. Key Rem. MOQ
H
Quick chain tensioner mounting kit; 1123 007 1008 1
consisting of items 1 to 11:
Chain sprocket cover; 1123 640 1700 1 1
including items 2 to 4:
Adjusting wheel 1123 648 2200 2 101
Screw P3 x 10 9104 003 8600 3 10
Cover plate 1123 648 3800 4 1
Wingnut 1123 660 1000 5 1
Collar screw 1123 664 2402 6 10
Tensioning gear; 1123 660 3000 7 1
including item 8:
Screw M4 x 5 9041 319 0600 8 10
Spiked bumper 1123 664 0501 9 5
Screw DG 5 x 16 (2x) 9075 478 4115 10 1)
Screwdriver 0812 370 1145 11 1)
Remarks
1) Part is already supplied for other models
Last Technical Information on models 021, 023, 025: 38.94
Waiblingen, February 1, 1995 Andreas Stihl - D1/MTK-st
1995 Andreas Stihl Technical Documentation 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.