Husqvarna Rider 18 ProFlex Instruction manual

101 90 99-26
Rider 18 ProFlex
Rider 20 ProFlex
Workshop Manual

62– English

English – 1
Safety regulations ...............................................2
General instructions .........................................2
Special instructions ..........................................2
Special tools ........................................................3
Technical data .....................................................4
Dimensions ......................................................4
Engine..............................................................4
Gear box ..........................................................4
Electrical system ..............................................4
Tightening moments.........................................4
Mowing deck ....................................................5
Control points...................................................5
Play ..................................................................5
Delivery and dealer service................................6
Maintenance schedule........................................8
Delivery measures ............................................10
Installing wheel weights .................................10
Refilling battery acid.......................................10
Fastening steering wheel ...............................10
Fastening support wheels ..............................10
Installing tow hitch..........................................10
Design and function.......................................... 11
General .......................................................... 11
Engine............................................................12
Steering..........................................................13
Driving............................................................14
Mowing deck ..................................................15
Reparation instructions....................................16
Removing engine ...........................................16
Replacing engine ...........................................18
Changing engine oil .......................................21
Checking and adjusting steering wires ..........21
Replacing steering wires................................22
Removal/installation of steering axle .............22
Removal/installation of wire wheel.................23
Checking and adjusting brake wire ................24
Checking and adjusting throttle control..........24
Checking and adjusting differential lock.........25
Replacing articulated steering bearing...........26
Removal of swing axle ...................................28
Replacing bushings........................................29
Workshop manual
Rider 18 ProFlex
and
Rider 20 ProFlex
Contents
Installation of swing axle ................................29
Removal/installation of hydrostatic
transmission...................................................31
Replacing hydrostatic transmission axle
sealing collars ................................................33
Input axle ..................................................33
Outgoing axles ..........................................34
Replacing hydrostatic transmission wire........35
Removal of hyrostatic transmission wire...35
Refitting hydrostatic transmission wire......37
Hydrostatic transmission brake......................40
Removal of brake......................................40
Installation of brake...................................40
Adjustment of brake ..................................41
Ineffective brake power.............................42
Bleeding hydrostatic transmission
oil system .......................................................42
Adjustment of transmission neutral position ..43
Transmission maintenance ............................45
Oil change......................................................45
Removal of belt ..............................................46
Assembling the belt........................................46
Checking and adjusting mower deck ground
pressure .........................................................47
Checking and adjusting mower deck
parallelism......................................................47
Adjusting cutting height area..........................48
Adjusting cutting height..................................48
Removal of mowing deck...............................49
Replacing mowing deck belts ........................50
Belt replacement on Bio deck ...................50
Belt replacement on mowing deck with
side- or rear discharge ..............................51
Removal of blades with bearings ...................52
Grinding and balancing of blades ..................53
Pulse air valve intake filter .............................54
Cleaning the filter ......................................54
Trouble shooting schedule ..............................55
Electrical system...............................................56
Circuit diagram...............................................56

2– English
Safety regulations
General instructions
The workshop handbook is written for personnel who
are assumed to have general ride-on mower
reparation and service know-how.
The workshop where the ride-on mower is repaired
should be equipped with safety devices in
accordance with local regulations.
No-one should attempt to repair the ride-on mower
without having first read and understood the contents
of this handbook.
The machine is tested for safety and approved only
for equipment supplied or recommended by the
manufacturer.
The below-mentioned boxes are included in this
workshop handbook, as is appropriate.
Special instructions
The fuel used in the ride-on mower has the
following hazardous characteristics:
• Toxic fluid and fumes
• Can cause eye and skin complaints
• Can cause breathing difficulties
• Highly flammable
When using compressed air, do not direct the
compressed air stream towards your, or anybody
else's, body.Air can be forced into the blood
stream, thereby constituting a danger to life .
Use hearing protectors when test driving.
After test driving, do not touch the silencer before it
has cooled down. Risk of burn injuries. This
especially applies if the ride-on mower is equipped
with a catalytic converter. If consumed, the lining on
and in the catalytic converter element is dangerous
to health. Use protective gloves when working with
the catalytic converter/silencer.
The blades are sharp and can cause cutting
injuries. Always use protective gloves when you are
handling the blades.
Use protective glasses when working with the
mowing deck. If the belt's tension spring comes off
and flies upwards, this can cause injury to persons.
Be extra careful when handling battery acid. Spilling
acid on the skin can cause severe burn injuries. If
acid is spilt on the skin, rinse immediately with
water. If acid gets into the eyes, this can cause
blindness. Contact a doctor.
Be careful with the maintenance of the battery.
Explosive gas is formed in the battery. Never
handle the battery when smoking or in the vicinity of
naked flames or sparks. Otherwise, the battery can
explode and cause severe injuries.
IMPORTANT INFORMATION
This box indicates a risk of damage to the
material if the instructions are not
followed.
WARNING!
The warning box indicates a
risk of injury to persons if the
instructions are not followed.
!

English – 3
Special tools
The following special tools are used when working on the ride-on mower.
506 56 76-01 Ball-ended Allen key 5/16" to unscrew the engine pulley socket head cap screw (Kawazaki).
506 66 48-01 Puller for engine pulley.
506 79 06-01 Ball-ended Allen key 3/8" to unscrew the engine pulley socket head cap screw (Briggs &
Stratton).
506 89 92-01 Holder-on for engine pulley removal.
506 89 93-01 Tool for removing steer return spring.
506 66 48-01 506 79 06-01506 57 00-01 506 89 92-01506 56 76-01 506 89 93-01

4– English
Technical data
Dimensions: Rider 18 ProFlex Rider 20 ProFlex
Length, base machine 2 030 mm 2 030 mm
Width, base machine 900 mm 900 mm
Height 1 100 mm 1 100 mm
Kerb weight, base machine 272 kg 334 kg
Wheel base 940 mm 940 mm
Track 720 mm 720 mm
Tyre size 18 x 7.50 x 8 18 x 7.50 x 8
Tyre pressure, front & rear 60 kPa (0,6 kp/cm2) 60 kPa
Max. gradient 15° 15°
Engine: Rider 18 ProFlex Rider 20 ProFlex
Manufacture Briggs & Stratton Briggs & Stratton
Vanguard V-Twin Vanguard V-Twin
model 350777 model 351777
type 1138, trim E1 type 1130, trim E1
Power 13,7/18 kW/hp 14,7/20 kW/hp
Displacement 570 cm3570 cm3
Fuel min 85 octane unleaded min 85 octane unleaded
Tank volume 10 litres 10 litres
Oil SAE 30 or 10W/30 SAE 30 or 10W/30
class CD-CF class CD-CF
Oil capacity 1,4 litres 1,4 litres
Oil volume incl. filter 1,6 litres 1,6 litres
Start Electric start Electric start
Gearbox: Rider 18 ProFlex Rider 20 ProFlex
Manufacture Tuff Torq K 61 Tuff Torq K 66
Oil SAE 10W/30 SAE 10W/30
class CD-CF class CD-CF
Oil capacity 3,3 litres 2,5 litres
Electrical system Rider 18 ProFlex Rider 20 ProFlex
Type 12 V, negative earth 12 V, negative earth
Battery 12 V, 24 Ah 12 V, 24 Ah
Spark plug Champion RC12YC Champion RC12YC
electrode gap = 0.7-0.8 mm electrode gap = 0.7-0.8 mm
Tightening moments
Carrier steering 5–10 Nm
Pulley steering wire 20–30 Nm
Belt wheel 35–40 Nm
Blades 45–50 Nm
Blade bearings 20–25 Nm
Belt tensioner wheel 15–25 Nm
Holder screws, engine 20–25 Nm
Holder screws, gear box 20–25 Nm
Brake drum bolts hydrostatic transmission 27 Nm
Engine pulley 70–80 Nm
Wheel axle nut 100–150 Nm

English – 5
Technical data
Control points
Mowing deck parallelism with cutting height in pos. 1: ± 2 mm
Cutting height control in pos. 1: Bio = 45 ± 2 mm
Other = 40 ± 2 mm
Synchronous transmission belt tension Bio 103 at 10 N force, impression: 7 mm
Dist. between support plate and drive belt: 3–6 mm
Distance belt tensioner control lever
and belt guide, disengaged unit: 17 ± 5 mm
Play
Clutch wire: 8–10 mm
Brake control lever against stop bolt: 0–1 mm
Brake control lever: 7–9 mm
Brake wire hydrostatic transmission: 0 mm
Mowing deck Rear ejector 120 BioClip 103
Cutting width 1 200 mm 1 030 mm
Cutting heights 7 settings, 40-100 mm 7 settings, 45-105 mm
Blade length 440 mm 410 mm
Sound level 100 dB(A) 100 dB(A)
Width 1 305 mm 1 115 mm
Weight 60 kg 53 kg
Length with cutting unit 2 390 mm 2 310 mm
Mowing deck Side ejector 97 Rear ejector 97
Cutting width 970 mm 970 mm
Cutting heights 7 settings, 40-80 mm 7 settings, 40-100 mm
Blade length 350 mm 350 mm
Sound level 100 dB(A) 100 dB(A)
Width 1 300 mm 1 075 mm
Weight 53 kg 49 kg
Length with cutting unit 2 380 mm 2 370 mm

6– English
Delivery and dealer service
Pre-delivery service
1. Top up battery with acid and recharge for four hours.
2. Fit steering wheel, seat and any optional equipment.
3. Fit cutting unit.
4. Adjust cutting unit:
Adjust lift springs (effective weight of cutting unit should be
12–15 kg, or set to maximum lift if brush is to be fitted).
Adjust cutting unit so that rear edge is about 2–4 mm higher than front edge.
Adjust cutting unit height setting so that cutting height limit is 5 mm above the frame of the unit at the
lowest cutting height.
5. Check that engine has correct amount of oil.
6. Check and adjust tyre pressure (60 kPa, 0.6 bar).
7. Connect battery.
8. Fill with fuel and start engine.
9. Check that machine does not move in neutral.
10. Check:
Forward drive.
Reverse drive.
Operation of blades.
Seat safety switch.
Lift lever safety switch.
Parking brake safety switch.
11. Check engine revs 3,000–3,100 rpm.
12. Tell customer about:
Need and benefits of following the service schedule.
Need and benefits of having machine serviced every 300 hours.
Servicing and the influence of this journal on the second-hand value of the machine.
Range of applications for BioClip.
13. Complete proof of sale, etc.
After first 5 hours
1. Change engine oil.

English – 7
Dealer service
25 hour service
1. Change engine oil (50 hours).
(25 hours if operating conditions severe).
2. Clean/replace air pre-filter or oil-foam element if
fitted (25 hours).
(more regularly in dusty working conditions)
3. Clean/replace air filter cartridge (25 hours, 100
hours if pre-filter fitted).
(more regularly in dusty working conditions)
4. Clean engine cooling air intake.
50 hour service
1. Change engine oil.
2. Clean/replace air pre-filter or oil-foam element if
fitted.
3. Clean/replace air filter cartridge (25 hours, 100
hours if pre-filter fitted)
(more regularly in dusty working conditions)
4. Clean engine cooling air intake.
5. Check/adjust cutting height setting.
6. Check/adjust parking brake.
7. Inspect flame guard/spark arrestor (optional
equipment)
100 hour service
1. Change engine oil.
2. Clean/replace air pre-filter or oil-foam element if
fitted.
3. Clean/replace air filter cartridge (25 hours, 100
hours if pre-filter fitted).
(more regularly in dusty working conditions)
4. Check/adjust cutting height setting.
5. Check/adjust parking brake.
6. Inspect flame guard/spark arrestor (optional
equipment)
7. Replace engine oil filter.
8. Clean/replace spark plug.
9. Replace fuel filter in fuel line.
10.Clean pulse-air filter.
11.Clean cooling system.
12.Check engine valve clearance.
13. Check need for oil change and filter change for
K66 gearbox (every 500 hours).
300 hour service
1. Change engine oil.
2. Replace air filter (pre-filter).
3. Replace air filter (paper).
4. Check/adjust cutting height setting.
5. Check/adjust parking brake.
6. Inspect flame guard/spark arrestor (optional
equipment)
7. Replace engine oil filter.
8. Clean/replace spark plug.
9. Replace fuel filter in fuel line.
10.Clean pulse-air filter.
11.Clean cooling system.
12.Check engine valve clearance.
13. Check need for oil change and filter change for
K66 gearbox (every 500 hours).
14. Carry out 300 hour service at authorised dealer.
At least once a season
1. Change engine oil (50 hours).
(25 hours in severe operating conditions).
2. Clean/replace air pre-filter or oil-foam element if
fitted (25 hours).
(more regularly in dusty working conditions)
3. Clean/replace air filter cartridge (25 hours, 100
hours if pre-filter fitted).
(more regularly in dusty working conditions)
4. Check/adjust cutting height setting.
5. Check/adjust parking brake.
6. Inspect flame guard/spark arrestor, optional
equipment
(50 hours).
7. Replace engine oil filter (100 hours).
8. Clean/replace spark plug (100 hours).
9. Replace fuel filter in fuel line (100 hours).
10.Clean pulse-air filter.
11.Clean cooling system (100 hours).
(more regularly in dusty working conditions)
12.Check engine valve clearance (100 hours).
13.Replace oil and filter in K66 gearbox (every 500
hours).
14.Carry out 300 hour service at authorised dealer.
Delivery and dealer service

8– English
Maintenance schedule
Maintenance interval in
hours
Daily main-
tenance
before after
Weekly3)
main-
tenance
At least
once a
year
Check for fuel and oil leakage - ❍
Check the parking brake - ❍
Check the engine oil level (when you
refuel) - ❍
Check the fuel pump air filter - ❍
Check the seat safety switch - ❍
Check the lift lever safety switch - ❍
Check the parking brake safety switch - ❍
Check/clean the engine cooling air intake - ❍
Check the cutting unit: - ❍
• blades are secure 53 ●
• condition of blades (sharpness,
shape, etc.) 55 ●
• blade synchronisation (90° between
BioClip) 52 ●
Check steering wires (for play, etc.) 23 ●
Check fasteners (screws, nuts, etc.) - ❍
Start engine and blades, listen for noise - ❍
Clean underside of cutting unit - ❍
Clean transmission air intake - ❍
Check battery acid level 10 ●
Check transmission oil level - ❍
Check condition of V-belts, pulleys, etc. - ❍
Check for damage - ❍
Check tyre pressures (60 kPa) - ❍
Check for damage to wire guide at
articulated joint - ❍
Clean thoroughly around engine - ❍
Clean air filter (pre-filter) - ❍
Clean thoroughly around transmission - ❍
Clean all belts, pulleys, etc. - ❍
Lubricate pivot (nipple) - ❍
Lubricate belt tensioner (nipple) - ❍
Lubricate triangle link (nipple) - ❍
Lubricate seat suspension - ❍
Lubricate all wires - ❍
Lubricate safety lock on cutting unit - ❍
Lubricate inner stud on cutting unit - ❍
Lubricate slot for cutting unit tool frame - ❍
Lubricate bearing surfaces on cutting unit - ❍
Clean inside frame tunnel - ❍
Lubricate pedal mechanism inside frame
tunnel - ❍
25 50 100 300
PageMaintenance
The following is a list of the maintenance which should be conducted on the machine. Most of the points that
are not covered by this workshop manual are covered by the operator’s manual.

English – 9
1) First change after 5 hours.2)When driving with a heavy load or when the ambient temperature is high, replace every 25 hours. Clean
every 25 hours if pre-filter is not fitted. Clean and replace the filter more often in dusty conditions. 3) For daily use of the machine
lubrication should be conducted twice a week. 4) Conducted by authorised service workshop.
!WARNING!
No service procedures must be conducted on the engine or cutting unit unless:
●= Covered by this workshop manual.
❍= Not covered by this workshop manual.
Maintenance interval in
hours
Daily main-
tenance
before after
Weekly3)
main-
tenance
At least
once a
year 25 50 100 300
PageMaintenance
Lubricate throttle control - ❍
Lubricate choke control - ❍
Smörj styrkedja i ramtunnel. - ❍
Lubricate steering chain inside frame
tunnel - ❍
Clean engine cooling air intake - ❍❍
Clean pre-filter or oil-foam element,
if fitted - ❍❍
Clean air filter cartridge2) -❍❍ ❍
Change engine oil1) 21 ●●
Check/adjust cutting height setting 47 ●●
Check/adjust parking brake 24 ●●
Inspect flame guard/spark arrestor
(optional equipment) - ❍❍
Replace engine oil filter - ❍❍
Clean/replace spark plugs - ❍❍
Replace fuel filter in pipe - ❍❍
Clean pulse-air filter 55 ●●
Clean cooling system - ❍❍
Check engine valve clearance4) -❍❍
Check whether oil change4) or filter
change4) are necessary for K66 gearbox
(every 500 hrs) - ❍❍
Replace air filter (pre-filter)2) -❍❍
Replace air filter (paper filter)2) -❍❍
Carry out 300 hour service4) -❍❍
• The engine is switched off.
• The ignition key is removed.
• The ignition cables are removed
from the plugs.
• The parking brake is applied.
• The cutting unit is disengaged.
Maintenance schedule

10– English
!
Refilling battery acid
The battery is delivered dry from the factory.
• Slowly fill the battery acid up to the mark on the
battery.
• Wait 20 minutes and fill, as is required, with more
battery acid.
• Charge the battery (12 V, 6 A) for four hours.
• Check the level of acid and fill, as is required,
with distilled water up to the correct level.
WARNING!
The battery acid is highly corrosive. Use
rubber gloves and protective glasses. Avoid
breathing in the acid fumes.
Measures for contact with acid
External: Rinse thoroughly with water.
Internal: Drink large quantities of water or
milk. Contact a doctor as soon as
possible.
Eyes: Rinse thoroughly with water.
Contact a doctor as soon asap.
The battery gives off explosive gas. Sparks,
naked flames and cigarettes must absolutely
not be in the near vicinity of the battery.
• Fasten the steering wheel with steering column
on the steering shaft.
• Tighten the socket head cap screw, make sure
that it sits in its groove on the steering shaft.
• Securely lock the socket head cap screw with the
locking nut.
Fastening steering wheel
Fastening support wheels
Fasten the support wheels with axles, spacers and
nuts in the support wheels holder.
Delivery measures
Installing wheel weights, Rider 20 ProFlex
Wheel weights are supplied with the Rider 20
ProFlex; these should be installed by the dealer.
Installing tow hitch
The tow hitch is supplied separately with the Rider.
This should be fitted by the dealer.

English – 11
Design and function
General
Husqvarna Riders is a series of ride-on mowers
with a large capacity. There are six sizes, from the
smallest Rider 11 to the largest Rider 20 ProFlex.
This manual refers mainly to the smaller machines;
the larger ProFlex machines are covered by a
separate manual. All Riders have articulated
steering in order to easily cut around trees and
other obstacles. Moreover, they all have front-
mounted mowing decks for controlled cutting and
for best possible cutting results.
Husqvarna Riders can, moreover, be equipped
with various accessories such as moss rake and
dozer blade which make them flexible working
tools throughout the year.
The Rider 18 ProFlex and Rider 20 ProFlex are
only available with hydrostatic transmission.
Rider 18 ProFlex and Rider 20 ProFlex can be equipped with 4 different mowing decks.
Bak 97 or 120 (rear ejection)
Sido 97 (side ejection)
Bio 103

12– English
Design and function
Engine
All Husqvarna Riders have engines from Briggs &
Stratton. The Rider 18 ProFlex and Rider 20
ProFlex have twin-cylinder air-cooled engines.
More intricate engine repairs are not described in
this workshop handbook, these can instead be read
in Briggs & Stratton's own handbooks which contain
detailed information about adjusting and repairing
the engines. The handbooks can be ordered from
an authorized service workshop.
The order numbers for the respective Rider models
are found in the table below. Please state these
when ordering manuals:
Model B & S model no.
Rider 18 ProFlex 350777
Rider 20 ProFlex 351777
It is important that only original spare parts are
used when repairing the engines. If other parts are
used, the guarantee shall no longer be valid.
Rider 18 ProFlex and Rider 20 ProFlex have two-
cylinder overhead valve engines with pressure
lubrication and a separate oil filter. These engines
are equipped with catalytic converters that reduce
hydrocarbon and nitrogen oxide emissions by up to
65% and carbon monoxide emissions by up to
45%.

English – 13
Design and function
Steering
All the ride-on mowers in Husqvarna's Rider-series
have articulated steering. The steering force from
the steering wheel is transferred to the rear section
via wires and a chain. This ensures that the ride-on
mower is easy to manoeuvre, as well as having
high-precision steering. A Rider easily cuts around
all obstacles that may be found on the lawn.
Thanks to the articulated steering, the turning
radius is extremely small, the uncut circle when the
steering wheel is fully turned is just 20–30 cm
depending on which model is chosen.
Outline diagram of the articulated steering function.
Rider machines have a sliding bearing (1) on the
steering column.

14– English
Design and function
Driving
Rider 18 ProFlex and Rider 20 ProFlex are
equipped with hydrostatic transmission which
provides the driver complete control. Continuously
variable speed control, forwards and reverse, is by
means of a foot pedal.
The Rider 20 ProFlex also has a differential lock
that allows the rear wheels to be driven
independently.
The differential lock is engaged and disengaged by
means of a pedal on the left-hand side of the
machine.
Hydrostatic transmission on Rider 18 ProFlex. Hydrostatic transmission on Rider 20 ProFlex.

English – 15
Mowing deck
The entire Rider series is equipped with front-
mounted mowing decks to ensure effective cutting
even in confined areas.
Rider 18 ProFlex and rider 20 ProFlex can be
delivered with a choice of mowing decks, with rear
ejection, side ejection or Bio.
Design and function
Bio 103
Mowing deck with side ejection.
Mowing deck with rear ejection

16– English
Reparation instructions
Removing engine
3
1
24
Remove the battery's fixing belt. Remove the safety
guard and remove the cable connections. Then, lift
out the battery.
Remove the cable which leads from the starter
relay to the start motor.
Mark up and remove the engine's electrical
connections.
Remove the clamps which hold the throttle and
choke wires. Unhook the wires from their
attachment in the carburettor.

English – 17
Reparation instructions
6
57
Remove the fuel line hose clamp from the fuel
pump and pull the fuel line downwards.
Remove the cover plate over the silencer (two
screws on either side of the silencer) and lift out the
plate.
Remove the exhaust pipe clamps and the silencer’s
four retaining bolts. Then remove the silencer,
exhaust pipe and the accompanying pulse air valve.
8
Clamp together the wire holder under the engine
pulley with a pair of flat pliers and pull the wire
holder downwards.

18– English
Reparation instructions
10
Remove the engine attachments, two on each side
of the engine, and remove the engine from the
mower.
Insert tool no. 506 79 06-01 into the centre of the
engine pulley. Unscrew and remove the socket
head cap screw which holds the pulley and the
engine axle together. Use tool no. 506 89 92-01 as
a holder-on. Remove the pulley from the engine
axle.
IMPORTANT INFORMATION
When installing the engine, it is important
that the pulley groove (1) is in a position so
the outgoing axle key (2) fits into the groove
(see diagram). Also check that both spacing
collars (3) and the key (2) are firmly attached
on the engine axle. Grease the engine axle.
Replacing engine
9
1
Lower the engine and tighten the engine
attachments (two on each side of the engine) with
moment (25 Nm).