wsm STW37 Workshop Manual page 82

STW34, STW37, STW40, WSM
Symptom
Engine Revolution Is
Not Smooth
Either White or Blue
Exhaust Gas Is
Observed
Either Black or Dark
Gray Exhaust Gas Is
Observed
Tractor Operator
Feels Deficient
Engine Output
Probable Cause and
Checking Procedure
1. Fuel filter is clogged or
dirty.
2. Air cleaner element is
clogged.
3. Fuel leak due to loose
injection pipe retaining nut.
4. Injection nozzle is stuck or
clogged.
5. Crankshaft, camshaft,
piston or bearing is seized.
6. Compression is leaking
from cylinder.
7. Valve timing is improper.
8. Piston and cylinder is worn
out.
9. Valve clearance is
incorrect.
1. Engine oil is excessive.
2. Piston ring and cylinder is
worn or stuck.
1. Tractor is operated under
overload condition.
2. Low grade fuel is used.
3. Fuel filter is clogged.
4. Air cleaner element is
clogged.
5. Injection nozzle is stuck or
clogged.
1. Engine's moving parts is
stuck.
2. Injection pump is
damaged.
3. Injection nozzle stuck or
clogged.
4. Compression is leaking.
5. Air cleaner element is dirty
or clogged.
Solution
Replace fuel filter.
Clean or replace air cleaner element.
Tighten retaining nut.
Replace or repair injection nozzle.
Repair or replace crankshaft, camshaft,
piston or bearing.
Replace head gasket, tighten cylinder
head bolt, glow plug and nozzle holder.
Correct valve timing.
Replace piston and cylinder.
Adjust valve clearance.
Reduce is to specified level engine oil.
Replace piston ring and cylinder.
Reduce the load.
Use specified fuel.
Replace fuel filter.
Clean or replace air cleaner element.
Replace or repair injection nozzle.
Repair or replace engine's moving parts.
Replace injection pump.
Replace or replace injection nozzle.
Check the compression pressure and
repair piston ring or cylinder
(engine crankcase).
Clean or replace air cleaner element.
1-S3
ENGINE
Reference
Page
G-25
G-24
1-S47
1-S19
1-S55,
1-S57,
1-S60,
1-S61
1-S49,
1-S58,
1-S64,
1-S72,
1-S77
1-S14
1-S72
1-S14
G-8
1-S72
–
G-8
G-25
G-24
1-S19
–
1-S51
1-S19
1-S12,
1-S72
G-24
KiSC issued 11, 2014 A