Kohler K91 Service Manual page 45

7 . Install the idle speed adjusting screw and
spring .
8 . Install t h e idle fuel adjusting needle a n d spring .
Turn the adjusting needle
bottoms l i g htly.
CAUTION : The tip of the idle fuel adjusting needle is
tapered to critical dimensions . Damage to
the needle and the seat in carburetor body
will result if the needle is forced .
9 . Turn the idle fuel needle
wise) from lightly bottomed according to the
instructions in the Adjustment " section of this
I I
Bul letin .
HIGH ALTITUDE OPERATION (FIXED J ET)
When operating the engine at high altitudes the
main fuel mixture tends to get overrich . An over­
rich mixture can cause conditions such as black .
sooty exhaust smoke , misfiring , loss of speed and
power, poor fuel economy, and poor o r slow gov­
ernor response .
To , compensate for this , a special high altitude
main fuel jet is available for each carburetor . The
high altitude m ain fuel jet is sold in a kit which in­
cludes the jet and necessary gaskets .
High Altitude Jet I nstal lation (Fixed Jet)
1 .
Remove the fuel bowl retaining screw. retain-
ing screw gasket . fuel bowl, and bowl gasket .
NOTE : If necessary, remove the air cleaner and
carburetor from engine to make fuel bowl removal
easier.
2 . Remove the float pin , float , and fuel inlet
needle .
3 . Remove t h e existing main fuel jet .
in
(clockwise) until it
out
(counterclock­
4 . Install t h e new h i g h altitude main fuel jet and
1 2/ 1 6 In. lb.
torque to
5. Reinstall the fuel inlet needle , float , and float
pin .
6 . Install the new bowl gasket from kit and the
fuel bowl . Make sure the bowl gasket and bowl
are centered and positioned properly to ensure
a good seal .
7 . Install the new bowl retaining screw gasket
from kit and the bowl retaining screw. Torque
45/55 in. lb.
screw to
8. Reinstall the carburetor and air cleaner to en­
gine as necessary using the new gaskets from
kit.
I DLE ADJUSTMENT PROCEDURE FOR
K341 AQS ENGINES WITH ANTI-DIESELING
SOLENOID
The idle speed of some vibro-mounted K34 1 AQS
engines has been increased to allow smoother OP-
eration at low idle and an anti-dieseling solenoid
has been added to prevent dieseling during shut-
down at the higher idle speed . If called upon to
adjust the idle on any K34 1 AQS engine with this
solenOid , use the following procedure. Refer to
Figure 6-3 1 .
STEP 1 IDLE FUEL M IXTURE ADJUSTMENT: With
engine stopped . turn the idle fuel adjusting screw
all the way in (clockwise) until it bottoms lightly
then back out 1 12 turn.
STEP 2 - I DLE SPEED ADJUSTMENT: Start engine
and check idle speed with a hand tachometer.
Idl e , no load , speed should be 2 1 00 RPM . To set
the idle speed , loosen the jam nut on the anti­
dieseling solenoid and turn the solenoid in or out
until 2 1 00 RPM idle speed is attained - retighten
jam nut to lock solenoid in position .
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