308874
7
PROBLEM
CAUSE
SOLUTION
Pump output is low on
upstroke
Hose inlet screen (27) is clogged.
Clean inlet screen.
p
p
upstroke.
Piston ball (25) is not seating.
Service piston ball. See manual 308798.
Piston packings are worn or damaged.
Replace packings. See manual 308798.
O-ring (17) in displacement pump is worn or
damaged.
Replace o-ring. See manual 308798.
Pump output is low on down-
stroke or on both strokes
Hose strainer (27) is clogged.
Clean strainer screen.
p
p
stroke or on both strokes.
Piston packings are worn or damaged.
Replace packings. See manual 308798.
Intake valve ball is not seating properly.
Clean intake valve. See manual 308798.
Engine speed is too low.
Increase throttle setting. See manual 308873.
Clutch is worn or damaged.
Replace clutch. See page 10.
Paint leaks into wetcup.
Wetcup is loose.
Tighten wetcup just enough to stop leakage.
p
Throat packings are worn or damaged.
Replace packings. See manual 308798.
Displacement rod is worn or damaged.
Replace rod. See manual 308798.
Fluid delivery is low.
Inlet screen is clogged.
Clean inlet screen.
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Pressure setting is too low.
Increase pressure. See manual 308873.
Engine speed is too low.
Increase throttle setting. See manual 308873.
Fluid filter (318), tip filter or tip is clogged or
dirty.
Clean filter. See manual 308873. Or, see gun
instruction manual.
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).
Fluid is spitting from gun.
Air in pump or hose.
Check and tighten all fluid connections.
Reprime pump. See manual 308873.
Tip is partially clogged.
Clear tip. See gun instruction manual.
Fluid supply is low or empty.
Refill fluid supply. Prime pump. See manual
308873. 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 manual 308798.
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 manual 308873.
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.