Viking MB 650 T Manuel D'utilisation page 70

– Clean law mower housing. First
disconnect spark plug socket and, for
model MB 650 VE, also remove the
battery. ( 9.5)
– MB 650 VS, MB 655 RS, MB 655 VS,
MB 655 YS: Attach or replace throttle
cable.
Fault:
Starting problems or deteriorating engine
power
Possible cause:
– Lawn mower housing blocked.
– Mowing at an excessively low cutting
height or fast speed
– Water in fuel tank and carburettor;
carburettor blocked
– Contaminated fuel tank
– Dirty air filter
– Dirty spark plug
Remedy:
– Clean law mower housing. First
disconnect spark plug socket and, for
model MB 650 VE , also remove the
battery. ( 9.5)
– 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 overheating.
Possible cause:
– Oil level in engine too low.
– Cooling ribs dirty.
Remedy:
– Change engine oil. ( 8.6)
– Clean cooling ribs. ( 14.2)
68
Fault:
No drive when self-propulsion lever is
actuated.
Possible cause:
– MB 655 YS: Self-propulsion cable
incorrectly adjusted.
– Self-propulsion cable defective (e.g.
kinked).
– V-belt worn.
– Gearbox defective.
Remedy:
– MB 655 YS: Check cable adjustment.
( 14.11)
– Replace cable.
– Replace V-belt.
– Replace gearbox.
Fault:
Speed control not functioning
Possible cause:
– Driving speed lever moved in wrong
direction.
– Cable disengaged or defective
(e.g. kinked).
Remedy:
– Move driving speed lever in the correct
direction. ( 13.9)
– Attach or replace cable.
Fault:
Mowing channel blocked
Possible cause:
– Mowing blade is worn.
– Mowing grass which is too long or too
wet.
– MB 650 VS, MB 655 RS, MB 655 VS,
MB 655 YS: Engine speed is too low.
Remedy:
– Replace mowing blade. (
– Adapt cutting height and mowing speed
to mowing conditions. (
– MB 650 VS, MB 655 RS, MB 655 VS,
MB 655 YS: Set the throttle lever to the
Start position. (
Fault:
Poor cut, lawn turning yellow
Possible cause:
– Blade is blunt or worn.
– Mowing speed is too high in relation to
cutting height.
– MB 650 VS, MB 655 RS, MB 655 VS,
MB 655 YS: Engine speed is too low.
Remedy:
– Sharpen or replace blade (
( 14.4),
– Reduce mowing speed and/or select
correct cutting height (do not work at
lowest cutting height). (
– MB 650 VS, MB 655 RS, MB 655 VS,
MB 655 YS: Set throttle lever to Start
position. (
Fault:
Excessive vibration during operation
Possible cause:
– Blade fastening screw loose.
– Blade imbalance due to incorrect
sharpening or fracture.
– Cutting unit defective.
– Engine mounting loose.
Remedy:
– Tighten blade fastening screw. (
– Re-sharpen (balance) or replace blade.
( 14.5),
– Check blade, blade shaft and blade
fastening and repair if necessary.
– Tighten engine mounting bolts.
14.4)
12.), ( 9.4)
13.5)
14.5),
9.4), ( 13.9)
13.5)
14.4)
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