Dolmar PB-251.4 - Manual (Page 17)

Fault location
Fault System Observation Cause
Engine not starting or with
difficulty Ignition system Ignition spark O.K. Fault in fuel supply or compression system, mechanical
defect
No ignition spark STOP-switch operated, wiring fault or short circuit, spark
plug or connector defective, ignition module faulty
Fuel supply Fuel tank filled Incorrect choke position, carburetor defective, fuel supply
line bent or blocked, fuel dirty.
Compression No compression when
pulled over Cylinder bottom gasket defective, crankshaft seals
damaged, cylinder or piston rings defective or improper
sealing of spark plug
Mechanical fault Starter not engaging Broken starter spring, broken parts inside of the engine
Warm start problems Tank filled ignition spark
existing Carburetor contaminated, have it cleaned
Engine starts but dies Fuel supply Tank filled Incorrect idling adjustment, carburetor contaminated
Fuel tank vent defective, fuel supply line interrupted,
cable or STOP-switch faulty
Insufficient performance Several systems
may simultaneously
be affected Engine idling poor Air filter contaminated, carburetor contaminated, muffler
clogged, exhaust duct in the cylinder clogged
Operating time
Item
Before
operation
After
lubrication
Daily
(10h)
30h 50h 200h
Shutdown
/rest
Corres-po
nding P
Inspect/clean ○ 9
Engine oil
Replace ○ *1 14
Tightening parts
(bolt, nut)
Inspect ○ 16
Clean/inspect ○ ―
Fuel tank
Drain fuel ○ *3 16
Throttle lever Check function ○
Stop switch Check function ○ 11
Low-speed rotation Inspect/adjust ○ 12
Air cleaner Clean ○ 15
Ignition plug Inspect ○ 15
Cooling air duct Clean/inspect ○ 16
Inspect ○ 16
Fuel pipe
Replace ◎ *2 ―
Fuel filter Clean/replace ○ 16
Clearance between air intake
valve and air discharge valve
Adjust ◎ *2 ―
Oil tube Inspect ◎ *2
Engine overhaul ◎ *2 ―
Carburetor Drain fuel ○ *3 16
*1 Perform initial replacement after 20h operation.
*2 For the 200 operating hour inspection, request Authorized Service Agent or a machine shop.
*3 After emptying the fuel tank, continue to run the engine and drain fuel in the carburetor.
17
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