Linhai ATV 500-D T3 EFI Service Manual page 42

CHAPTER 3 ENGINE
3.2. Troubleshooting
Operation Notice................................................................................3.2.1
Starting Failure/Hard Starting................................................................3.2.1
Unstable Engine Running or Engine Stops...............................................3.2.2
Poor Engine Performance in High-speed Range or Slow Speed Rising..........3.2.3
Unstable Idle Speed...........................................................................3.2.4
Poor Engine Performance in Middle or High Range...................................3.2.5
Operating Notice
This chapter is a general explanation of major troubleshooting of the whole engine.
Refer to the relevant chapters for troubleshooting not listed in this chapter.
Starting Failure/Hard Starting
In case of starting failure or hard starting, refer to chapter of starting system (Engine maintenance
notebook) for troubleshooting and check the starting system whether have problems or not.
Loosen drain screw, check if fuel
has reached carburetor
Reached
Remove spark plug and mount it
to spark plug cap, get it earthed
and check spark
Normal spark
Measure compression pressure
Normal compression pressure
Try starting as operation
Engine cannot be started
Remove spark plug and check
again
Dry spark plug
Remove carburetor over 30
minutes, connect ethylene pipes
with fuel increment loop and blow
No Fuel
Weak spark or
No spark
Low or no
Compression
Nearly start, but
starting failure
Wet spark plug
No Air current
LH500ATV-D T3 EFI SERVICE MANUA 19.0
No fuel in fuel tank
Clogged fuel hose
Clogged float valve
Clogged fuel filter
Clogged fuel tank cap breather hole
Faulty spark plug
Stained or damaged spark plug
Faulty high tension coil or short circuit
Faulty Ignition coil or short circuit
Faulty ignition switch
Faulty CDI unit
Faulty pickup coil
Faulty cylinder head (Engine Service)
Worn or damaged Cylinder and piston
ring
Faulty cylinder gasket
Deteriorated fuel
Improper idle speed adjustment
Secondary air intake into air intake pipe
Improper ignition time
Clogged air filter
Carburetor overflow
Excessive opening of throttle
Clogged air filter
Faulty fuel enrichment device
CHAPTER 3 ENGINE
.
PAGE. 3- 9