Cub Cadet LT1042 Operator's Manual page 24

• Make sure fuel is reaching the carburetor. Check
the fuel lines and fuel pump for restrictions or faulty
components, replace as necessary.
• Make sure the air cleaner element is clean and all
air cleaner element components are secure.
If, after checking the items listed above, the engine is
hard to start, runs roughly, or stalls at low idle speed, it
may be necessary to adjust or service the carburetor.
Adjustment
NOTE:
Engines may have a fixed idle or limiter cap on
the idle fuel adjusting screw. Step 2 can only be
performed within the limits allowed by the cap.
1. Start the engine and run at half throttle for five to 10
minutes to warm up. The engine must be warm
before performing steps 2 and 3.
2. Low Idle Fuel Screw Setting: Place the throttle
into the "idle" or "slow" position. Turn the low idle
fuel mixture screw out (counterclockwise) from the
preliminary setting until engine speed decreases
(rich). Note the position of the screw. Now turn the
mixture screw in (clockwise). The engine speed
may increase, then it will decrease as the screw is
turned in (lean). Note the position of the screw. Set
the adjusting screw midway between the rich and
lean settings. See Figure 19.
Adjust to Midpoint
Rich
Figure 19
3. Low Idle Speed Setting: Place the throttle control
into the "idle" or "slow" position. Set the low idle
speed to 2150 RPM* (± 75 RPM) on Models
LT1042 & LT1045 (1500 RPM* (± 75 RPM) on
Models LT1046 & LT1050) by turning the low idle
speed adjusting screw in or out. Check the speed
using a tachometer.
NOTE:
idle fuel Screw, the low idle speed must not exceed
2150 RPM (± 75 RPM) on Models LT1042 & LT1045
and 1200 RPM* (± 75 RPM) on Models LT1046 &
LT1050).
Lean
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To ensure best results when setting the low