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