Kohler ECV940 Service Manual page 25

Left Gauge Regulated Pressure
Selection
80 PSI
Recommended for engines over 200
cc or those exhibiting high leakage at
35 PSI setting.
35 PSI
Recommended for single cylinder
walk-behind push mower
applications.
Percentage of leakage 0%
Test Result
Gauge reading in low
(green) zone.
Gauge reading in
moderate (yellow)
zone.
Gauge reading in
high (red) zone.
Confi rm consecutive leakdown
test has been performed AFTER
engine has been operated under
normal load conditions.
62 690 05 Rev. H
Test Pressure Chart for Dual Gauge Tool
80 72 64
35 31.5 28 24.5
10% 20% 30%
Green Zone
Leakdown Test Results
Condition
Piston rings and cylinder in
good condition.
Air escaping from crankcase
breather and/or dipstick tube.
Air escaping from exhaust.
Air escaping from intake.
Air escaping from crankcase
breather and/or dipstick tube.
Air escaping from exhaust.
Air escaping from intake.
KohlerEngines.com
Right Gauge Reading in PSI
56 48 40 32
21 17.5 14
40% 50% 60%
Yellow Zone
Action
No further action required.
Some wear present causing leakage from
combustion chamber to crankcase. Repair not
required at this time if breather system is
functioning normally.
Exhaust valve leakage present, possibly due to
carbon deposits. Repair not required. Carbon
cleaning could be performed to reduce leakage.
Intake valve leakage present, possibly due to
carbon deposits. Repair not required. Carbon
cleaning could be performed to reduce leakage.
Excess wear present causing leakage from
combustion chamber to crankcase. Breather
system will not function normally and will fail
crankcase vacuum test if this condition is truly
present. Engine disassembly and analysis
required to determine root cause and
correction.
Excess exhaust valve leakage present, possibly
due to carbon deposits and/or valve to seat
sealing issues. Carbon cleaning may reduce
leakage. Valve grind and/or component
replacement may be necessary. Excess oil
consumption and/or excess heat is a suspect
cause and must be resolved to prevent
reoccurrence.
Excess intake valve leakage present, possibly
due to carbon deposits and/or valve to seat
sealing issues. Carbon cleaning may reduce
leakage. Valve grind and/or component
replacement may be necessary. Excess oil
consumption through intake valve and/or
excess heat is a suspect cause and must be
resolved to prevent reoccurrence. Inspect
breather system components and intake valve
stem sealing.
Troubleshooting
24 16 8 0
10.5 7 3.5 0
70% 80% 90% 100%
Red Zone
25