Viking MB 756 GS Gebrauchsanleitung Seite 53

– Connect spark plug socket; check
connection between ignition lead and
socket
– Remove spark plug and dry; set throttle
lever to STOP position and pull recoil
starter rope several times with spark
plug removed; screw in spark plug and
connect spark plug socket @
– Clean/replace air filter @
– Repair throttle cable
Fault:
Starting problems or deteriorating engine
power
Possible cause:
– Mowing at an excessively low cutting
height or fast speed
– Water in fuel tank and carburettor;
carburettor blocked
– Fuel tank contaminated
– Air filter dirty
– Spark plug dirty
Remedy:
– Adapt cutting height and reduce
mowing speed
– Empty fuel tank, clean fuel line and
carburettor
– Clean fuel tank
– Clean/replace air filter @,
– Clean spark plug
Fault:
Engine cuts out during operation
Possible cause:
– Fuel cock closed
– Tank ventilation screw closed
– Blade brake clutch overloaded
Remedy:
– Open the fuel cock ( 10.1)
– Open the tank ventilation screw
( 10.1)
0478 111 9925 C - EN
– Clean the mowing channel, empty the
grass catcher bag ( 9.)
Fault:
No drive when self-propulsion lever is
actuated
Possible cause:
– Self-propulsion cable incorrectly
adjusted
– Self-propulsion cable damaged
(e.g. kinked)
– V-belt worn
Remedy:
– Check the adjustment (
– Replace the cable
– Replace the V-belt
Fault:
Engine overheating
Possible cause:
– Oil level in engine too low
– Cooling ribs dirty
Remedy:
– Perform an engine oil change if
necessary @
– Clean cooling ribs ( 11.3)
Fault:
Poor cut, lawn turning yellow
Possible cause:
– Mowing blade is blunt or worn,
– Rate of feed is too high in relation to the
cutting height
– Engine speed is too low
Remedy:
– Re-sharpen or replace mowing blade
( 11.6)
– Reduce rate of feed and/or select
correct cutting height ( 9.), (
– Set the throttle lever to the Start
position (
Fault:
Mowing channel blocked
Possible cause:
– Mowing blade is worn
– Mowing grass which is too long or too
wet
– Engine speed is too low
Remedy:
– Replace the mowing blade (
– Adapt the cutting height and mowing
11.9) speed to the mowing conditions (
( 7.3)
– Set the throttle lever to the Start
position (
Fault:
Excessive vibration during operation
Possible cause:
– Cutting unit defective
– Mowing blade imbalance
– Engine mounting loose
Remedy:
– Check mowing blade, blade shaft and
blade fastening screws; tighten blade
fastening screws (
– Re-sharpen/replace mowing blade
( 11.8)
– Tighten engine mounting bolts
Fault:
Petrol runs out of the tank cap when the
machine is placed in the cleaning position
Possible cause:
– Tank ventilation screw was tightening
too firmly
7.3) Remedy:
– Replace tank cap
10.1)
11.6)
9.),
10.1)
11.7)
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