Appendix A, Carburettor - Epa Models - Jonsered CS 2141 Workshop Manual

Carburetors - EPA-models
Basic adjustment for EPA II carburetors valid from
January 2002
After replacing the carburetor or high speed and/or
low speed needle on an EPA (The US Environmental
Protection Agency) certifi ed product a basic adjust-
ment must be carried out as described below in order
to meet the EPA-requirements. This to achieve as low
emissions as possible. This instruction is made for
USA & Canada only.
On EPA carburetors both the H- and L-needles are
fi tted with caps to prevent the chain saw operator from
changing the adjustment above EPA standard. The
caps can be removed to achieve richer or leaner ad-
justments. To set the needles correctly an adjustment
sleeve is fi tted from the factory over the caps to lock
them in maximum allowed settings.
When correctly set the caps must be fi xed on the nee-
dles. The adjustment sleeve then can be removed.
NOTE! Before making any adjustments the follow-
ing must be done!
• Mount, for this model, approved bar & chain com-
bination (See Technical data in the Operator's
manual).
Model CS 2141/CS 2145/CS 2150
Model CS 2149/CS 2152
Model CS 2147/CS 2156/CS 2159
• The chain should not be tensioned more than that it
remains ~0,2 inches to the bar.
• Mount a new air fi lter.
Replacement of the H-needle or complete carbure-
tor
1. Screw the new H-needle to the bottom and turn it
counterclockwise "A" turns.
Model CS 2141/CS 2145/CS 2150
Model CS 2149/CS 2152
Model CS 2147/CS 2156/CS 2159
2. Check that:
The H-cap is adjusted to its richest setting. (Turned
counterclockwise to stop.). The cap is not fi xed to
the needle, it should rotate independently. Adjust
the L-cap to a center position (1/4 turn counterclock-
wise = minimum, 1/4 turn clockwise = maximum).
3. Start the engine. If necessary, adjust the idling
speed with the T-screw until the chain stops.
4. Adjust the H-needle to give a top speed of "B" rpm.
Model CS 2141/CS 2145/CS 2150
Model CS 2149/CS 2152
Model CS 2159
Model CS 2147
Model CS 2156
Use a narrow blade screwdriver (Ref.no. 531 00
48-63) and insert it through the hole in the cap (max.
blade width 2 mm/0.08 inch).
Appendix A
5. Let the engine run at "B" rpm ~ 1 minute, until
warm.
6. Adjust the H-needle to a top speed of "C" rpm.
Model CS 2141/CS 2145/CS 2150
Model CS 2149/CS 2152
Model CS 2156
Model CS 2147
Model CS 2159
7. Check that the H-cap is still adjusted to its richest
setting. (Turned counterclockwise to stop). NOTE!
The H-needle must not rotate!
8. Gently knock the H-cap into position. Use a 5
mm/0.2 inch mandrel (for ex. the locking pin for the
bevel gear ref.no. 502 02 61-03).
This is a basic carburetor adjustment. Further fi ne
adjustments, within the limits the caps allow, may be
necessary to achieve optimum performance. See the
Operator's manual.
Replacement of the L-needle
1. Take off the cap from the L-needle using e.g. a pair
of cutting pliers and unscrew the needle.
2. Screw the new L-needle to the bottom and then turn
it counterclockwise 1 1/2 turns.
15"
3. Press a new L-cap on the L-needle to the fi rst stop,
15"
which means that the cap is not fi xed to the needle,
16"
it should rotate independently.
4. Adjust the L-cap to the richest position (turned
counterclockwise to stop) without turning the nee-
dle.
5. Let the engine run at ~ "E" app.1 minute until warm
and then let it run on idle.
Model CS 2141/CS 2145/CS 2150
Model CS 2149/CS 2152
Model CS 2159
A = 3/4
Model CS 2147
A = 3/4
Model CS 2156
A = 3/4
6. Adjust the idle speed to 2 700 rpm.
7. Adjust the L- needle until the highest possible idling
speed is achieved and then turn the
L-needle 1/2 turn counterclockwise. Use a narrow
blade screwdriver w. ref.no.
531 00 48-63 and insert through the hole in the cap
(max. blade width 2 mm/0.08 inch)
NOTE! If the chain rotates, turn the idling speed
screw (T) counterclockwise until the chain stops.
8. Check that the L-cap is still adjusted to its richest
B = 12 000
position. (Turned counterclockwise to stop)
B = 12 000
NOTE! The L-needle must not rotate!
B = 12 500
9. Gently knock the L-cap into position. Use a 5
B = 13 000
mm/0.2 inch mandrel (for ex. the locking pin for the
B = 13 500
bevel gear ref.no. 502 02 61-03).
This is a basic carburetor adjustment. Further fi ne
adjustments, within the limits the caps allow, may be
necessary to achieve optimum performance. See the
Operator's manual.
Repair instructions
C = 13 700
C = 13 700
C = 13 100
C = 14 300
C = 14 000
E = 12 000
E = 12 000
E = 12 500
E = 13 000
E = 13 500
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