Graco LineLazer IV 3900 Manual

Repair -- Parts List
LineLazer™IV 3900, R300, 5900, and
FieldLazer R300 Airless Line Stripers
- For application of line striping materials -
3300 psi (228 bar, 22.8 MPa) Maximum Working Pressure
311020V
Important Safety Instructions
Read all warnings and instructions in this
manual. Save these instructions.
248862
311017
312540
310643
311254
309055
311049
EN

3110202
Table of Contents
Models 3........................................
Warnings 4......................................
Spray Tip Selection Table 6........................
Maintenance 7...................................
Troubleshooting 8................................
Repair
Bearing Housing & Connecting Rod 11............
Drive Housing 12...............................
Pinion Assembly/Clutch Armature/Clamp 13.......
Engine 16.....................................
Pressure Control 17............................
Trigger Sensor Adjustment 19...................
Distance Sensor Adjustment 19..................
Control Board Diagnostics 20....................
Displacement Pump 21.........................
Parts
LineLazer IV 3900/R300/5900 22.................
Drive and Pinion Housing Assemblies 23..........
Pressure Control Wiring Diagram 34................
Technical Data 35................................
Dimensions 35...................................
Graco Phone Number 35..........................
Graco Warranty 36...............................

311020 3
Models
3900
248862 n n
248863 n n
249008 n n
249009 n n
248864 n n n
248865 n n n
R300
24M605 n n n n
24M607 n n
5900
248866 n n
248867 n n
249010 n n
249011 n n
248868 n n n
248869 n n n

3110204
Warnings
The following Warnings are for safe setup, use, grounding, maintenance and repair of this equipment. The exclamation
point symbol alerts you to a general warning and the hazard symbols refer to procedure--specific risks. Refer back to
these Warnings.
WARNING
FIRE AND EXPLOSION HAZARD
Flammable fumes, such as solvent and paint fumes, in work area can ignite or explode. To help prevent fire
and explosion:
DUse equipment only in well ventilated area.
DDo not fill fuel tank while engine is running or hot; shut off engine and let it cool. Fuel is flammable and
can ignite or explode if spilled on hot surface.
DEliminate all ignition sources; such as pilot lights, cigarettes, portable electric lamps, and plastic drop
cloths (potential static arc).
DKeep work area free of debris, including solvent, rags and gasoline.
DDo not plug or unplug power cords, or turn power or light switches on or off when flammable fumes are
present.
DGround equipment and conductive objects in work area. See Grounding instructions.
DUse only grounded hoses.
DHold gun firmly to side of grounded pail when triggering into pail.
DIf there is static sparking or you feel a shock, stop operation immediately. Do not use equipment until
you identify and correct the problem.
DKeep a fire extinguisher in work area.
CARBON MONOXIDE HAZARD
Exhaust contains poisonous carbon monoxide, which is colorless and odorless. Breathing carbon monoxide
can cause death. Do not operate in an enclosed area.
SKIN INJECTION HAZARD
High--pressure fluid from gun, hose leaks, or ruptured components will pierce skin. This may look like just a
cut, but it is a serious injury that can result in amputation. Get immediate surgical treatment.
DDo not point gun at anyone or at any part of the body.
DDo not put your hand over the spray tip.
DDo not stop or deflect leaks with your hand, body, glove, or rag.
DDo not spray without tip guard and trigger guard installed.
DEngage trigger lock when not spraying.
DFollow Pressure Relief Procedure in this manual, when you stop spraying and before cleaning, check-
ing, or servicing equipment.
PRESSURIZED EQUIPMENT HAZARD
Fluid from the gun/dispense valve, leaks, or ruptured components can splash in the eyes or on skin and
cause serious injury.
DFollow Pressure Relief Procedure in this manual, when you stop spraying and before cleaning, check-
ing, or servicing equipment.
DTighten all fluid connections before operating the equipment.
DCheck hoses, tubes, and couplings daily. Replace worn or damaged parts immediately.
PRESSURIZED ALUMINUM PARTS HAZARD
Do not use 1,1,1--trichloroethane, methylene chloride, other halogenated hydrocarbon solvents or fluids
containing such solvents in pressurized aluminum equipment. Such use can cause serious chemical reac-
tion and equipment rupture, and result in death, serious injury, and property damage.

311020 5
WARNING
EQUIPMENT MISUSE HAZARD
Misuse can cause death or serious injury.
DDo not exceed the maximum working pressure or temperature rating of the lowest rated system compo-
nent. See Technical Data in all equipment manuals.
DUse fluids and solvents that are compatible with equipment wetted parts. See Technical Data in all
equipment manuals. Read fluid and solvent manufacturer’s warnings.
DCheck equipment daily. Repair or replace worn or damaged parts immediately.
DDo not alter or modify equipment.
DUse equipment only for its intended purpose. Call your Graco distributor for information.
DRoute hoses and cables away from traffic areas, sharp edges, moving parts, and hot surfaces.
DDo not kink or over bend hoses or use hoses to pull equipment
DKeep children and animals away from work area.
DComply with all applicable safety regulations.
BURN HAZARD
Equipment surfaces and fluid that’s heated can become very hot during operation. To avoid severe burns,
do not touch hot fluid or equipment. Wait until equipment/fluid has cooled completely.
MOVING PARTS HAZARD
Moving parts can pinch or amputate fingers and other body parts.
DKeep clear of moving parts.
DDo not operate equipment with protective guards or covers removed.
DPressurized equipment can start without warning. Before checking, moving, or servicing equipment,
follow the Pressure Relief Procedure in this manual. Disconnect power or air supply.
PERSONAL PROTECTIVE EQUIPMENT
You must wear appropriate protective equipment when operating, servicing, or when in the operating area
of the equipment to help protect you from serious injury, including eye injury, inhalation of toxic fumes,
burns, and hearing loss. This equipment includes but is not limited to:
DProtective eyewear.
DClothing and respirator as recommended by the fluid and solvent manufacturer.
DGloves.
DHearing protection.
RECOIL HAZARD
Brace yourself; gun may recoil when triggered and cause you to fall, which could cause serious injury.

3110206
Tip Selection
in.
(cm)
in.
(cm) in.
(cm) in.
(cm)
LL5213* 2(5) n
LL5215* 2(5) n
LL5217 4 (10) n
LL5219 4 (10) n
LL5315* 4 (10) n
LL5317 4 (10) n
LL5319 4 (10) n
LL5321 4 (10) n
LL5323 4 (10) n
LL5325 4 (10) n
LL5327 4 (10) n
LL5329 4 (10) n
LL5331 4 (10) n
LL5333 4 (10) n
LL5335 4 (10) n
LL5355 4 (10) n
LL5417 6 (15) n
LL5419 6 (15) n
LL5421 6 (15) n
LL5423 6 (15) n
LL5425 6 (15) n
LL5427 6 (15) n
LL5429 6 (15) n
LL5431 6 (15) n
LL5435 6 (15) n
LL5621 12 (30) n
LL5623 12 (30) n
LL5625 12 (30) n
LL5627 12 (30) n
LL5629 12 (30) n
LL5631 12 (30) n
LL5635 12 (30) n
LL5639 12 (30) n
* Use 100 mesh filter to reduce tip clogs

311020 7
Maintenance
Pressure Relief Procedure
1. Lock gun trigger safety.
2. Turn engine ON/OFF switch to OFF.
3. Move pump switch to OFF and turn pressure
control knob fully counterclockwise.
4. Unlock trigger safety. Hold metal part of gun firmly
to side of grounded metal pail, and trigger gun to
relieve pressure.
5. Lock gun trigger safety.
6. Open pressure drain valve. Leave valve open until
ready to spray again.
If you suspect that the spray tip or hose is completely
clogged, or that pressure has not been fully relieved
after following the steps above, VERY SLOWLY
loosen tip guard retaining nut or hose end coupling to
relieve pressure gradually, then loosen completely.
Now clear tip or hose.
C
A
UTION
DMinimum hose size allowable for proper sprayer
operation is 3/8 in. x 50 ft
DFor detailed engine maintenance and specifica-
tions, refer to separate Honda Engines Owner’s
Manual, supplied.
DAILY: Check engine oil level and fill as necessary.
DAILY: Check hose for wear and damage.
DAILY: Check gun safety for proper operation.
DAILY: Check pressure drain valve for proper opera-
tion.
DAILY: Check and fill the gas tank.
AFTER THE FIRST 20 HOURS OF OPERATION:
Drain engine oil and refill with clean oil. Reference
Honda Engines Owner’s Manual for correct oil viscos-
ity.
WEEKLY: Remove air filter cover and clean element.
Replace element, if necessary. If operating in an
unusually dusty environment: check filter daily and
replace, if necessary.
Replacement elements can be purchased from your
local HONDA dealer.
WEEKLY: Check level of TSL in displacement pump
packing nut. Fill nut, if necessary. Keep TSL in nut to
help prevent fluid buildup on piston rod and premature
wear of packings.
AFTER EACH 100 HOURS OF OPERATION:
Change engine oil. Reference Honda Engines Owner’s
Manual for correct oil viscosity.
SPARK PLUG: Use only BPR6ES (NGK) or
W20EPR--U (NIPPONDENSO) plug. Gap plug to
0.028 to 0.031 in. (0.7 to 0.8 mm). Use spark plug
wrench when installing and removing plug.
Caster Wheel
(See letter call-outs in Parts drawing on page 28)
1. Once each year, tighten nut (127) under dust cap
(142) until spring washer bottoms out. Then back
off the nut 1/2 to 3/4 turn.
2. Once each year, tighten nut (127) on screw (131)
until it begins to compress spring washer. Then
tighten the nut an additional 1/4 turn.
3. Once each month, grease the wheel bearing (F).
4. Check pin (55) for wear. If pin is worn out, there
will be play in the caster wheel. Reverse or re-
place the pin as needed.
5. Check caster wheel alignment as necessary.
To align: loosen screw (145), align wheel and
tighten screw.

3110208
Troubleshooting
PROBLEM CAUSE SOLUTION
E=XX is displayed Fault condition exists Determine fault correction from table, page 20.
Engine won’t start Engine switch is OFF Turn engine switch ON
Engine is out of gas Refill gas tank. Honda Engines Owner’s Manual.
Engine oil level is low Try to start engine. Replenish oil, if necessary.
Honda Engines Owner’s Manual.
Spark plug cable is disconnected or damaged Connect spark plug cable or replace spark plug
Cold engine Use choke
Fuel shutoff lever is OFF Move lever to ON position
Oil is seeping into combustion chamber Remove spark plug. Pull starter 3 to 4 times.
Clean or replace spark plug. Start engine.
Keep sprayer upright to avoid oil seepage.
Engine operates, but dis-
placement pump does not
operate
Error code displayed? Reference pressure control repair. Page 18.
Pump switch is OFF TurnpumpswitchON.
Pressure setting is too low Turn pressure adjusting knob clockwise to
increase pressure.
Fluid filter (11) is dirty Clean filter. Page 32.
Tip or tip filter is clogged Clean tip or tip filter. See spray gun manual.
Displacement pump piston rod is stuck due to
dried paint
Repair pump. See pump manual.
Connecting rod is worn or damaged Replace connecting rod. Page 11.
Drive housing is worn or damaged Replace drive housing. Page 12.
Electrical power is not energizing clutch field Check wiring connections. Page 16.
Reference pressure control repair. Page 18.
Reference wiring diagram. Page 34.
With pump switch ON and pressure turned to
MAXIMUM, use a test light to check for power
between clutch test points on control board.
Measure resistance across clutch coil. At 70_
F, the resistance must be between 1.2 ±0.2Ω
(LineLazer IV 3900/R300); 1.7 ±0.2Ω(LineLaz-
er IV 5900); if not, replace pinion housing.
Have pressure control checked by authorized
Graco dealer.
Clutch is worn, damaged, or incorrectly
positioned
Replace clutch. Page 13.
Pinion assembly is worn or damaged Repair or replace pinion assembly. Page 13.

311020 9
Troubleshooting
PROBLEM CAUSE SOLUTION
Pump output is low Strainer (34f) is clogged Clean strainer.
Piston ball is not seating Service piston ball. See pump manual.
Piston packings are worn or damaged Replace packings. See pump manual.
O-ring in pump is worn or damaged Replace o-ring. See pump manual.
Intake valve ball is not seating properly Clean intake valve. See pump manual.
Intake valve ball is packed with material Clean intake valve. See pump manual.
Engine speed is too low Increase throttle setting. See operation manual.
Clutch is worn or damaged Replace clutch. Page 13.
Pressure setting is too low Increase pressure. See operation manual.
Fluid filter (11), tip filter or tip is clogged or dirty Clean filter. See operation or spray gun manu-
al.
Large pressure drop in hose with heavy
materials
Use larger diameter hose and/or reduce overall
length of hose. Use of more than 100 ft of 1/4
in. hose significantly reduces performance of
sprayer. Use 3/8 in. hose for optimum perfor-
mance (50 ft minimum).
Excessive paint leakage into
throat packing nut
Throat packing nut is loose Remove throat packing nut spacer. Tighten
throat packing nut just enough to stop leakage.
Throat packings are worn or damaged Replace packings. See pump manual.
Displacement rod is worn or damaged Replace rod. See pump manual.
Fluid is spitting from gun Air in pump or hose Check and tighten all fluid connections.
Reprime pump. See operation manual.
Tip is partially clogged Clear tip. See spray gun manual.
Fluid supply is low or empty Refill fluid supply. Prime pump. See operation
manual. Check fluid supply often to prevent
running pump dry.
Pump is difficult to prime Air in pump or hose Check and tighten all fluid connections.
Reduce engine speed and cycle pump as
slowly as possible during priming.
Intake valve is leaking Clean intake valve. Be sure ball seat is not
nicked or worn and that ball seats well. Reas-
semble valve.
Pump packings are worn Replace pump packings. See pump manual.
Paint is too thick Thin the paint according to the supplier’s
recommendations
Engine speed is too high Decrease throttle setting before priming pump.
See operation manual.
Clutch squeaks each time
clutch engages
Clutch surfaces are not matched to each other
when new and may cause noise
Clutch surfaces need to wear into each other.
Noise will dissipate after a day of run time.
High engine speed at no
l
o
a
d
Misadjusted throttle setting Reset throttle to 3600 engine rpm at no load
l
oa
d
Worn engine governor Replace or service engine governor

31102010
Troubleshooting
PROBLEM CAUSE SOLUTION
Gallon counter not working Broken or disconnected wire Check wires and connections. Replace
broken wires.
Bad sensor Replace sensor
Missing magnet Reposition or replace magnet.
Sprayer operates, but display does not Bad connection between control board
and display
Remove display and reconnect
Display damaged Replace display
Distance counter not operating properly Trigger sensor not set correctly See “Spray icon does not show on dis-
play when fluid is sprayed”
Bad wiring connections Check connector, and reconnect
Distance sensor not spaced correctly
from gear
Adjust space between sensor and gear
to .050 --/+ .020 in. See page 19.
Distance sensor and gear not aligned Remove tire, and press in or pull out
gear to align sensor and gear.
Gear teeth missing or damaged. Replace distance gear/wheel
Wire cracked or broken Replace sensor
Mils not calculating Distance sensor See “Distance counter not operating
properly”
Trigger sensor See “Spray icon does not show on dis-
play when fluid is sprayed”
Gallon counter See “Gallon counter not working”
Bad or damaged control board Replace control board
Fluid spray starts after spray icon is
shown on display
Interrupter (164) is improperly positioned Turn screw (126) counterclockwise until
spray icon synchronizes with fluid spray
Fluid spray starts before spray icon is
shown on display
Interrupter (164) is improperly positioned Turn screw (126) clockwise until spray
icon is synchronized with fluid spray
Spray icon does not show on display
when fluid is sprayed
Loose connector Check connector and reconnect
Interrupter (164) is improperly positioned Turn screw (126) counterclockwise until
spray icon synchronizes with fluid spray
Reed switch assembly (166) is damaged Replace reed switch assembly (166)
Magnet on assembly (166) is missing Replace reed switch assembly (166)
Cut or sliced wire Replace distance sensor harness (66)
Control board is damaged Replace control board
Display is damaged Replace display
Spray icon is always shown on display Interrupter (164) is improperly positioned Turn screw (126) clockwise until spray icon
is synchronized with fluid spray
Reed switch assembly (166) is damaged Replace reed switch assembly (166)

311020 11
Bearing Housing and Connecting Rod
Removal
1. Relieve pressure, page 7.
2. Fig. 2. Remove screws (187) and front cover (83).
3. Unscrew suction tube (34) from pump, hold
wrench on pump intake valve (A) to keep pump
from loosening.
4. Disconnect pump outlet hose (100) from displace-
ment pump outlet nipple (60).
5. Fig. 1. Use screwdriver to push up retaining spring
(236) at top of pump. Push out pin (235).
Fig. 1
7675B
235
236
6. Fig. 2. Loosen retaining nut (84). Unscrew and
remove displacement pump (21).
7. Remove four screws (183) and lockwashers (173)
from bearing housing (22).
8. Pull connecting rod (26) and lightly tap lower rear
of bearing housing (22) with plastic mallet to
loosen from drive housing (24). Pull bearing hous-
ing and connecting rod assembly (26) off drive
housing.
9. Inspect crank (B) for excessive wear and replace
parts as needed.
Installation
1. Evenly lubricate inside of bronze bearing (C) in
bearing housing (22) with high-quality motor oil.
Liberally pack top roller bearing (E), lower bearing
(D) inside connecting rod assembly (26) with
bearing grease.
2. Assemble connecting rod (26) and bearing
housing (22).
3. Clean mating surfaces of bearing and drive hous-
ings.
4. Align connecting rod with crank (B) and carefully
align locating pins (F) in drive housing (24) with
holes in bearing housing (22). Push bearing hous-
ing onto drive housing or tap into place with plastic
mallet.
C
A
UTION
DO NOT use bearing housing screws (183) to align
or seat bearing housing with drive housing. Align
these parts with locating pins (F), to avoid prema-
ture bearing wear.
5. Install screws (183) and lockwashers (173) on
bearing housing. Torque evenly to note 3 value in
Fig. 2.
6. Install pump. Refer to Displacement Pump,
Installation, page 21.
ti6395a
LineLazer IV 3900/R300: Torque to 200 in-lb
(22.6 N¡m)
Pack with bearing grease 114819
Oil
3
2
1
Fig. 2 Model 248862 shown
LineLazer V 5900: Torque to 25 ft-lb
E
2
C
1
235
187
83
173
3
D
A
34
34g
22
236
100
60
24
B
26
2
F
21
84
183
3

31102012
Drive Housing
Removal
1. Relieve pressure, page 7.
2. Fig. 3. Remove bearing housing. Do Bearing
Housing and Connecting Rod procedure on
page 11.
3. Remove two screws (158) and reed switch (182).
4. Remove six screws (189) from pinion housing (25).
5. Lightly tap around drive housing (24) to loosen
drive housing. Pull drive housing straight off pinion
housing. Be prepared to support gear cluster (23),
which may also come out.
Installation
1. Liberally apply bearing grease (supplied with
replacement gear cluster) to gear cluster (23) and
to areas called out by note 2.
2. Place bronze colored washer (24g) on shaft pro-
truding from large shaft of drive housing (24).
Place silver colored washer (24h) on pinion hous-
ing. Clean mating surfaces of pinion and drive
housings. Align gears and push new drive housing
straight onto pinion housing and locating pins (A).
3. Install six screws (189). Torque evenly to note 1
value in Fig. 3.
4. Install reed switch (182) with two screws (158).
5. Install bearing housing. Do steps 1. through 6. of
Bearing Housing and Connecting Rod proce-
dure on page 11.
ti6396a
Fig. 3
189
24h
24g
24
25
23
179
178
189
1
1
2
2
Apply remaining grease to these areas
173
182
181
158
178
1
LineLazer IV 3900/R300: Torque to 200 in-lb
(22.6 N¡m)LineLazer IV 5900: Torque to 25 ft-lb (34 N¡m)
2
A
A

311020 13
Pinion Assembly/Clutch Armature/Clamp
Pinion Assembly/Clutch Armature Removal
Pinion Assembly
If pinion assembly (25) is not removed from clutch
housing (85), do 1. through 3. Otherwise, start at 4.
1. Remove drive housing, page 12.
2. Fig. 12. Remove clip (251) and junction box (226).
3. Fig. 11. Disconnect pump stroke sensor and clutch
cables.
4. Fig. 4. Remove four screws (189) and lockwash-
ers (188) and pinion assembly (25).
ti5480b
189
188
189
188
Fig. 4
25
5. Fig. 5. Place pinion assembly (25) on bench with
rotor side up.
6. Remove four screws (170) and lockwashers (172).
Install two screws in threaded holes (E) in rotor.
Alternately tighten screws until rotor comes off.
Fig. 5
E
ti5481b
175
172
ti5987c
E
7. Fig. 6. Remove retaining ring (25e).
8. Tap pinion shaft (25d) out with plastic mallet.
ti5482b
Fig. 6
25e
25d
8703A
86
25c
Clutch Armature
9. Fig.7. Use an impact wrench or wedge something
between armature (87) and clutch housing to hold
engine shaft during removal.
10. Remove four screws (175) and lockwashers (172).
11. Remove armature (87).
Fig. 7
175
172
87
8704A

31102014
Installation
Clutch Armature
1. Fig. 8. Lay two stacks of two dimes on smooth
bench surface.
2. Lay armature (87) on two stacks of dimes.
3. Press center of clutch down on bench surface.
Fig. 8
87
8705A
0.12 ±.01 in. (3.0 ±.25 mm)
dimes
4. Install armature (87) on engine drive shaft.
5. Install four screws (175) and lockwashers (172)
with torque of 125 in-lb.
Pinion Assembly
6. Fig. 6. Check o--ring (25c) and replace if missing
or damaged.
7. Tap pinion shaft (25d) in with plastic mallet.
8. Install retaining ring (25e) with beveled side
facing up.
9. Fig. 5. Place pinion assembly on bench with rotor
side up.
10. Apply thread sealant to screws. Install four screws
(170) and lockwashers (172). Alternately torque
screws to 125 in-lb until rotor is secure. Use
threaded holes to hold rotor.
11. Fig. 4. Install pinion assembly (25) with five screws
(189) and lockwashers (188).
12. Fig. 11. Connect pump stroke sensor and clutch
cables.
13. Fig. 12. Install junction box (226) with clip (251).
Clamp
Removal
1. Do Engine Removal.
2. Drain gasoline from tank according to Honda
manual.
3. Tip engine on side so gas tank is down and air
cleaner is up.
4. Fig. 9. Loosen two screws (175) on clamp (82),
5. Push screwdriver into slot in clamp (82) and re-
move clamp.
Installation
1. Fig. 9. Install engine shaft key (88).
2. Tap clamp (82) on engine shaft (A) with plastic
mallet. Maintain dimension shown note 2. Chamfer
must face engine.
3. Check dimension: Place rigid, straight steel bar (B)
across face of clutch housing (5). Use accurate
measuring device to measure distance between bar
and face of clamp. Adjust clamp as necessary.
Torque two screws (175) to 125 ±10 in-lb (14 ±1.1
N¡m).
B
1
2
3
A
4
ti5484b
Fig. 9
1
3
2
Face of clutch housing
2.61 ±.010 in. (66.29 ±.25 mm); LineLazer lV 5900
Torque to 125 ±.10 in-lb (14 ±1.1 N¡m)
2.55 ±.010 in. (39.37 ±.25 mm); LineLazer lV 3900/R300
88
82
4Chamfer this side
85
175

311020 15
Clutch Housing
Removal
1. Fig. 10. Remove four cap screws (186) and lock
washers (188) which hold clutch housing (85) to
engine.
2. Remove screw (177) from under mounting
plate (96).
3. Pull off clutch housing (85).
Installation
1. Fig. 10. Push on clutch housing (5).
2. Install four cap screws (186) and lock washers
(188) and secure clutch housing (85) to engine.
Torque to 200 in-lb (22.6 NSm).
3. Install cap screw (177) from beneath mounting
plate (96). Torque to 26 ft-lb (35.2 NSm).
ti6643a
Fig. 10
186
188
85
88
177
96

31102016
Engine
Removal
1. Remove Pinion Assembly/Clutch Armature/
Clamp and Clutch Housing. See pages 11 -- 15.
2. Fig. 12. Remove clip (251) and junction box (226).
3. Fig. 11. Disconnect all necessary wiring.
4. Fig. 12. Remove screw (177). Remove two
screws (117), locknuts (118), and ground conduc-
tor (230, 260) from base of engine (185).
5. Lift engine carefully and place on work bench.
NOTE: All service to the engine must be performed by
an authorized HONDA dealer.
Main Control Box Cable
Wheel Sensor Cable
Bottom View
To Engine
ti6397a
To Ma in
Control
Box
Distance
Sensor
To
Engine
Junction
Box
Pump Stroke
Counter
Clutch
Fig. 11
ti6536a
Engine
ti6398a
Fig. 12
118
117
185
177
Ref.118
223
226
251
Installation
1. Lift engine carefully and place on cart.
2. Fig. 12. Install two screws (117) and ground con-
ductor (223, 260) in base of engine and secure
with locknuts (118). Torque to 20 to 30 ft--lb.
3. Fig. 11. Connect all necessary wiring.
4. Install Pinion Assembly/Clutch Armature/Clamp
and Clutch Housing. See pages 11 -- 15.

311020 17
Pressure Control
On/Off Switch
Removal
1. Relieve pressure, page 7.
2. Fig. 13. Remove two screws (125) and cover (31).
3. Pull display connector wings (A) open on PC board
and pull display connector out.
4. Disconnect ON/OFF switch connector (B) from PC
board.
5. Press in on two retaining tabs on each side of
ON/OFF switch (15g) and remove switch.
Installation
1. Install ON/OFF switch (15g) so tabs of switch snap
into place on inside of pressure control housing.
2. Connect ON/OFF switch connector (B) to PC
board.
3. Push display connector into PC board close dis-
play connector wings (A) on PC board.
4. Install cover (31) with two screws (125).
ENGINE
GROUND
ti6408a
Main Control
Box Cable
Transducer
Fig. 13
AB
15g
125
31
15d 15j
C
216
217
15o 15r
D
15i
15n

31102018
Pressure Control
Control Board
Removal
1. Relieve pressure, page 7.
2. Fig. 13. Remove two screws (125) and
control cover (31). Pull display connector wings
open on PC board and pull display connector out.
3. Figs. 13 and 21. Note on a paper lead connections
to the control board. Disconnect leads from control
board (15d).
4. Fig. 13. Remove four screws (15j) from control
board (15d).
Installation
1. Fig. 13. Install control board (15d) with four
screws (15j).
2. Figs. 13 and 21. Refer to note on lead connections
to the control board. Connect leads to control
board (15d).
3. Fig. 13. Push display connector into PC board
close display connector wings on PC board. Install
control cover (31) with two screws (125).
Pressure Control Transducer
Removal
1. Relieve pressure, page 7.
2. Fig. 13. Remove two screws (125) and
control cover (31).
3. Disconnect transducer lead (C) from control
board (15d).
4. Remove pressure control transducer (216) and
o-ring (217) from filter manifold (40).
Installation
1. Fig. 13. Install o-ring (217) and pressure control
transducer (216) in filter manifold (40). Torque to
35--45 ft-lb.
2. Connect transducer lead (C) to control
board (15d).
3. Install control cover (31) with two screws (125).
Pressure Adjust Potentiometer
Removal
1. Relieve pressure, page 7.
2. Fig. 13. Remove two screws (125) and
control cover (31).
3. Disconnect lead (D) from control board (15d).
4. Loosen set screws on potentiometer knob (15o)
and remove knob, shaft nut, lockwasher and
pressure adjust potentiometer (15i).
5. Remove seal (15n) from potentiometer (15i).
Installation
1. Install seal (15n) on potentiometer (15i).
2. Fig. 13. Install pressure adjust potentiometer (15i),
shaft nut, lockwasher and potentiometer
knob (15o).
a. Turn potentiometer shaft (15i) clockwise to
internal stop. Assemble potentiometer knob
(15o) to strike pin on plate (15r).
b. After adjustment of step a., tighten both set
screws in knob 1/4 to 3/8 turn after contact
with shaft.
3. Connect lead (D) to control board (15d).
4. Install control cover (31) with two screws (125).

311020 19
Trigger Sensor Adjustment
Refer to Troubleshooting for trigger sensor adjust-
ment, and see operation manual.
Distance Sensor Adjustment
Gear Alignment
1. Relieve pressure, page 7.
2. Fig. 14. Remove dust cap (142) from wheel.
Remove nut (127).
3. Remove wheel (120) from LineLazer.
4. Align gear (67) with sensor.
a. Pull gear out from wheel with gear puller.
b. Push gear in toward wheel with mallet.
5. Install wheel (120) on LineLazer.
6. Install nut (127) until tight, then back off 1/4 turn.
Install dust cap (142) on wheel.
Sensor Height Adjustment
1. Remove wheel (120) from LineLazer.
2. Remove distance sensor (66).
3. Adjust sensor assembly height with two 17 mm
nuts of sensor so bottom surface of sensor is
0.638 +/--0.020 from bottom surface of shield.
Torque to 8 +/-- 2 in-lb.
4. Reassemble distance sensor (66) and wheel (82).
Inside of tire
.638 in.
Tire
Distance
Sensor (66)
Gear (67)
Frame
Axle
ti6400a
Fig. 14
142
127
120
(120)
66
Distance Sensor Detail
Gear (67)

psi
bar
MPa
31102020
Control Board Diagnostics
Digital Display Messages
Relieve pressure before repair;page 7. No display does not mean that sprayer is not pressurized.
DISPLAY SPRAYER
OPERATION
INDICATION ACTION
No Display Sprayer may be pressurized. Loss of power or display
not connected
Check power source. Relieve
pressure before repair or disas-
sembly. Verify display is con-
nected.
Sprayer may be pressurized. Pressure less than
200 psi (14 bar, 1.4
MPa)
Increase pressure as needed
Sprayer is pressurized. Power is ap-
plied. (Pressure varies with tip size
and pressure control setting.)
Normal operation Spray
Sprayer stops. Engine is running. Exceeded pressure limit Remove any filter clogs or flow
obstructions. Make sure gun trig-
ger is locked open if using Auto-
Clean valve.
Sprayer stops. Engine is running. Pressure transducer
faulty, bad connection or
broken wire.
Check transducer connections
and wire. Replace transducer or
control board, if necessary.
Sprayer stops. Engine is running. High clutch current 1. Check clutch 7--pin bulkhead
connector. Clean contacts.
2. Measure 1.2 ±0.2Ω
(LineLazer IV 3900/R300);
1.7 ±0.2Ω(LineLazer IV
5900) across clutch field at
70_F
3. Replace clutch field assembly
After a fault, follow these steps to restart sprayer:
1. Correct fault condition
2. Turn sprayer OFF
3. Turn sprayer ON