Section 11: Trouble Shooting Guide - MTD 690 Operator's Manual

SECTION 11: TROUBLE SHOOTING GUIDE
Trouble Corrective Action
Engine will not
crank
Engine cranks
but will not start
Engine smokes
Excessive
vibration
Mower will not
discharge grass
or leaves uncut
strips
Possible
Cause(s)
Safety switch but-
ton not depressed.
Battery installed
incorrectly.
Battery is dead or
weak.
Blown fuse or cir-
cuit breaker.
Engine ground wire
loose.
Throttle or choke
not in starting posi-
tion.
No fuel to the car-
buretor.
No spark to spark
plug.
Dirty air cleaner.
Engine oil has
been overfitled.
Engine loses
crankcase
vacuum.
Bent or
damaged blade.
Bent blade.
Engine speed low.
Speed selection.
Cutting height set
too low.
Blades short or
dull.
There are two switches in the starting circuit of your unit: the brake pedal switch and the
PTO (blade engage) lever switch. Make certain the actuator is fully depressing the but-
tons on each switch.
The battery must be installed with negative terminal attached to black ground wire. Neg-
ative terminal is identified at the post by "NEG", "N" or "-". The positive terminal, identi-
fied by "POS", "P" or "+", must be attached to the big red wire which goes to the
solenoid. All batteries are to be fully charged before installing.
Charge with 6 AMP charger until fully charged.
Replace fuse with automotive type fuse. Fuses seldom fail without a reason. The prob-
lem must be corrected. Check for loose connections in the fuse holder. Replace fuse
holder if necessary. A dead short may be in the cranking or charging circuit where the
insulation may have rubbed through and exposed the bare wire. Replace the wire or
repair with electrician's tape if the wire strands have not been damaged.
Note: Look for a wire pinched between body panels, burned by the exhaust pipe or muf-
fler or rubbed against a moving part.
Engine should have a black ground wire running from engine to frame or mounting bolt.
Check operator's manual for correct position for throttle control and choke for starting.
Gasoline tank empty. Fill.
Fuel line or in-line fuel filter, if so equipped, plugged. Remove and clean fuel line.
Replace filter if necessary.
Spark plug lead disconnected. Connect lead.
Faulty spark plug. To test, remove spark plug. Attach spark plug lead to spark plug.
Ground the spark plug body against the engine block. Crank the engine. The spark plug
should fire at the electrode. Replace if it does not.
If the air cleaner is dirty, the engine may not start. Refer to the engine manual packed
with your unit.
Check oil level.
Dipstick not seated or broken. Replace damaged part.
Engine breather damaged. Replace.
Stop engine immediately. Check all pulleys, blade adapters, keys and bolts for
tightness and spindle damage. Tighten or replace any damaged parts.
Stop engine immediately. Replace damaged blade. Only use original equipment blades.
Throttle must be set at full throttle.
Use slower ground speed. The slower your ground speed, the better the quality of cut.
Raise deck.
Sharpen or replace blades (uncut strip problem only).
NOTE:
For repairs beyond the minor adjustments above, contact your local authorized service dealer.
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