Mack 946401 - Troubleshooting; Engine Will Not Start or Runs Poorly; Engine Overheats; Poor Trimming Performance

GB - 15
5. Remove the v-belt from the jackshaft
pulley.
6. Remove the capscrew and lock washer
from the engine sheave.
7. Lower the engine sheave past the belt
fingers and remove the belt.
To install the new belt:
1. Slide the new belt over the groove in the
engine sheave and slide the sheave
against the engine. Make sure the belt is
in the groove and is inside the belt fingers.
2. Install the capscrew and lock washer.
Tighten securely.
3. Slide the belt between the idler and belt
finger on the idler bracket.
4. Install the four tapping screws in the holes
in the frame, from the top side of the
frame.
5. Install the four jackshaft spacers on the
tapping screws.
6. Install the belt finger. Make sure the bent
tabs are facing up and are to the sides
and front of the unit.
7. Install the belt in the groove of the
jackshaft pulley.
8. Attach the jackshaft assembly to the
frame with the four tapping screws.
Fasten securely.
9. Reinstall the trimmer shield with the six
tapping screws.
TROUBLESHOOTING
PROBLEM PROBABLE CAUSE CORRECTION
Engine will
not start or
runs poorly
1. Spark plug wire disconnected.
2. Engine not primed
3. Fuel tank empty.
4. Throttle control lever not in
correct position.
5. Engine is flooded.
6. Defective or incorrectly gapped
spark plug.
7. Stale or contaminated gasoline.
8. Engine cooling system
overloaded with debris.
9. Dirty carburetor or fuel line.
10.Dirty air filter or precleaner.
11.Carburetor out of adjustment.
1. Connect spark plug wire.
2. Prime engine.
3. Add fuel to the fuel tank.
4. See Engine Manual.
5. Wait several minutes before
attempting to start.
6. Replace or regap spark plug.
7. Drain fuel tank and refill with
fresh gasoline.
8. Clean debris screen and
cooling fins.
9. Clean carburetor or fuel line.
See Engine Manual.
10.Replace air filter or
precleaner.
11.See Engine Manual or
contact your dealer.
Engine
overheats
1. Engine cooling system
overloaded with debris.
2. Carburetor out of adjustment.
1. Clean engine screen and
cooling fins.
2. See Engine Manual or
contact your dealer.
Poor
trimming
performance
1. Engine not set at Fast speed. 1. Set engine throttle to Fast
position.
Trimmer
vibrates
1. Cutter line lengths are too
uneven.
2. Loose hardware.
1. Trim or adjust cutter line to
equal lengths. Replace if
necessary.
2. Check all bolts and nuts,
including engine mounting
hardware, for tightness.