Cub Cadet GT-2550 - Manual (Page 23)

23
CARBURETOR ADJUSTMENTS
WARNING
When making adjustments to the carburetor
while the engine is running, disengage the PTO
clutch and engage the brake pedal lock. Keep
clear of all moving parts and be careful of all hot
surfaces.
WARNING
Carbon monoxide fumes can be fatal! Do not
make any adjustments to the carburetor in a
confined area such as a storage building. Move
the tractor outside into the air.
The carburetor is adjusted at the factory and under
normal operating conditions it will not require
readjusting. The high speed and idle fuel mixture
settings are made at the factory and cannot be
adjusted. If the engine does not operate properly and
the problem appears to be fuel system related, check
the following areas before adjusting the carburetor:
Refer to MAINTENANCE section.
• Check for fuel in fuel tank
• Check fuel cap vent for blockage
• Check fuel line for pinched or obstructed areas
• Check for fuel filter blockage
• Check for a clogged air filter
If, however, the engine is hard-starting or runs roughly
or stalls at low idle speed, it may be necessary to
adjust or service the carburetor.
The air filter element and element cover must be
assembled to the carburetor when running the engine.
There are no accessible mixture adjustment screws on
the carburetor. The only setting which can be changed
is the low idle speed.
NOTE
Carburetor adjustments should be made only
after the engine has warmed up.
1. Start the engine and run at half throttle for 5 to 10
minutes to warm up. The engine must be warm
before making the final settings. Check that the
throttle and choke plates can fully open.
2. Idle Speed Setting: Place the throttle control into
the “idle” or “slow” position. Set the low idle speed
to 1200 rpm (± 75 rpm) by turning the low idle
speed adjusting screw in or out. Check the speed
using a tachometer (See Figure 18).
Figure 18
3. If proper operation is not restored after adjusting the
low idle speed, carburetor servicing by your Cub
Cadet dealer may be required.
NOTE: AIR CLEANER COVER MUST
BE REMOVED TO ADJUST
CARBURETOR IDLE SPEED
IDLE SPEED
ADJUSTING SCREW
AND SPRING