Line Striper Trouble Shooting Guide

Problem

Cause

Solution

Engine won't start 1. Engine switch is OFF Turn engine switch ON
2. Engine is out of gas Refill gas tank.
3. Engine oil level is low Try to start engine. Replenish oil, if necessary. See Honda Engines Owner's Manual.
4. Spark plug cable is disconnected or damaged Connect spark plug cable or replace spark plug
5. Cold engine Use choke
6. Fuel shutoff lever is OFF Move lever to ON position
7. Oil is seeping into combustion chamber Remove spark plug. Pull starter rope 3 or 4 times. Clean or replace spark plug. Try to start engine. Keep sprayer upright to avoid oil seepage.
Engine operates, but displacement pump does not operate. Pressure control switch is OFF. Turn pressure control switch ON.
Pressure setting is too low. Turn pressure adjusting knob clockwise to increase pressure.
Fluid filter is dirty. Clean filter.
Tip or tip filter is clogged. Clean tip or tip filter. See gun instruction manual.
Displacement pump piston rod is stuck due to dried paint. Repair pump.
Connecting rod is worn or damaged. Replace connecting rod. See page 8.
Drive housing is worn or damaged. Replace drive housing.
Electrical power is not energizing field. Check wiring connections. Reference control board diagnostics. With pressure control switch ON and pressure turned to MAXIMUM, use a test light to check for power between clutch terminals on control board.

Remove black clutch wires from control board and measure resistance across wires. At 70° F, the resistance must be between 1.2 0.2Ω (LL 3900); 1.7 0.2Ω (LL 5900); if not, replace pinion housing.

Have pressure control checked by and authorized Graco dealer.
Clutch is worn, damaged, or incorrectly positioned. Replace clutch.
Pinion assembly is worn or damaged. Repair or replace pinion assembly, see pg. 10.
Pump output is low on upstroke Hose inlet screen is clogged. Clean inlet screen.
Piston ball is not seating. Service piston ball.
Piston packings are worn or damaged. Replace packings.
O-ring in displacement pump is worn or damaged. Replace O-ring.
Pump output is low on down stroke or on both strokes Hose strainer is clogged. Clean strainer screen.
Piston packings are worn or damaged. Replace packings.
Intake valve ball is not seating properly. Clean intake valve.
Engine speed is too low. Increase throttle setting.
Clutch is worn or damaged. Replace clutch
Paint leaks into wetcup. Wetcup is loose. Tighten wetcup just enough to stop leakage.
Throat packings are worn or damaged. Replace packings.
Displacement rod is worn or damaged. Replace rod.
Fluid delivery is low. Inlet screen is clogged. Clean inlet screen.
Pressure setting is too low. Increase pressure.
Engine speed is too low. Increase throttle setting.
Fluid filter, tip filter or tip is clogged or dirty. Clean filter.
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 performance
Fluid is spitting from gun. Air in pump or hose. Check and tighten all fluid connections. Reprime pump.
Tip is partially clogged. Clear Tip
Fluid supply is low or empty. Refill fluid supply. Prime pump. 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. Reassemble valve.
Pump packings are worn. Replace pump packings
Paint is too thick. Thin the paint according to the supplier's recommendations.
Engine speed is too high. Decrease throttle setting before priming pump.
Clutch squeaks each time clutch engages. Small irregularities of new clutch surfaces grind together and cause noise Clutch surfaces need to wear into each other. Noise will dissipate after a day of run time.
High engine speed at no load. Misadjusted throttle setting. Reset throttle to 3600–3800 engine rpm at no load.
Worn engine governor. Replace or service engine governor.
Low stall or run pressure shown on display. New pump or new packings. Pump break-in period takes up to 100 gallons of material.
Faulty transducer. Replace transducer.
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.
Displacement rod is worn or damaged. Replace rod.
Excessive leakage around hydraulic motor piston rod wiper. Piston rod seal worn or damaged. Replace these parts.
Distance counter not operating properly. Trigger sensor not set correctly. See "Spray icon does not show on display 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.
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 display 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 is improperly positioned. Turn screw counter-clockwise until spray icon synchronizes with fluid spray
Fluid spray starts before spray icon is shown on display. Interrupter (164) is improperly positioned. Turn screw clockwise until spray icon is synchronized with fluid spray
Spray icon does not show on display when fluid is sprayed. Loose connector. Check that 5-pin connector and reed switch are properly connected
Interrupter is improperly positioned. Turn screw counter-clockwise until spray icon synchronizes with fluid spray.
Reed switch assembly is damaged. Replace reed switch assembly
Magnet on assembly is missing. Replace reed switch assembly
A connector on wiring harness or on reed switch (18) is damaged.
  1. Disconnect reed switch and 5-pin connector from back of control board.
  2. Check continuity between pin 1 on 2-pin connector and pin 1 on 5-pin connector. Check continuity between pin 2 on 2-pin connector and pin 4 on 5-pin connector. If there is no continuity in either case, replace wiring harness.
  3. If there is continuity in both cases replace reed switch assembly
Cut or sliced wire. Replace wiring harness.
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 clockwise until spray icon is synchronized with fluid spray.
Reed switch assembly (18) is damaged. Replace reed switch assembly
Pressure control knob does not rotate. Knob is jammed. Pull back cover where remote cable connects to hydraulic pump and turn counter clockwise (ccw) until free.
Pressure control knob rotates freely with no pressure change. Remote cable broken or disconnected. Replace or reconnect cable.
Engine bounces when striping. Spring is broken, loose or missing. Replace or reconnect spring.
No dots or poor dots with ghosting No dots. Check that solenoid power cord is plugged in.
Check Remote button. Verify Remote button operation by changing angle in ANGLE CALC display
Solenoid cartridge bar is too far away from aerosol marking can spray tip. Do Auto-Layout Can Actuator Adjustment.
Poor dots or dots with ghosting. Solenoid cartridge bar is too close to aerosol marking can spray tip. Do Auto-Layout Can Actuator Adjustment.
Engine speed to slow Engine speed must be greater than 2600 rpm.
Aerosol can malfunctioning Check that can sprays. Replace if not.
Solenoid module malfunctioning Replace solenoid module