Linhai ATV 500-D T3 EFI, Service Manual

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CHAPTER 3 ENGINE
LH500ATV-D T3 EFI SERVICE MANUA 19.0
CHAPTER 3 ENGINE PAGE. 3- 134
oil, water, dirt and moist residues.
2- If the firing end of spark plug has oily or wet
deposit, brush the spark plug in an approved,
non-flammable and non-toxic solvent. Then
dry the spark plug thoroughly with compressed
air
3- Use a propane torch to dry wet-fuel fouled
plugs. Allow the torch flame to enter up the center
electrode insulator. Allow plug to cool down
4- If the spark plug threads have carbon & scale
deposits, clean with wire brush, taking care not
to injure the electrode or the insulator tip
electrodes
- Cleaning & re-gapping will not restore a used
spark plug to a new condition. It may be more
economical and efficient to replace used spark
plugs with new plugs instead of cleaning.
- Sooted plugs should be replaced
- Do not cool by using water or any liquid
- Clean threads permit easier installation and
proper seating which will maximize transfer heat
away from the plug
DO : Regap spark plugs to the exact measurement
specified by the engine manufacturer to keep the
best fuel economy and proper engine performance
- Use round wire-type gauge for an accurate
measure of gap on all used spark plugs
- when gapping a spark plug only the side
electrode
is moved. The center electrode must not be moved
- Too wide a gap could cause the plug to
misfire(higher required
ignition voltage).
- Too narrow of a gap could affect idle stability
- A flat gauge can’t accurately measure the spark
plug on used plugs
DO : When replacing spark plugs with new ones,
always use equivalent plugs with same heat range,
thread, size, etc….
- Higher heat range plug(hotter plug) could lead to
pre-ignition & possible piston damage
- Lower heat range (colder plug) could lead to cold
fouling & emission problem
DO : For installing spark plugs follow the
following
steps:
1- make sure the cylinder head threads and spark
plug threads are clean. Make sure the spark
plug thread is free of dings and burrs. If
necessary, use a thread chaser and seat
cleaning tool.
2- Make sure the spark plug gasket seat is clean,
then thread the gasket to fit flush against the
gasket seat. Tapered seat plugs do not require
gaskets
3- Screw the spark plugs finger-tight into the
cylinder head. Then, use a torque wrench to
tighten spark plugs following manufacturer’s
recommendation).
Torque is different for various plug type & cylinder
head material
- If the thread is damage, it prevents a good heat
transform from the shell to the cylinder head
- Do not use any type of anti-seize compound on
spark plug threads. Doing this will decrease the
amount of friction between the threads. The result
of the lowered friction is that when the spark plug
is torqued to the proper specification, the spark
plug is turned too far into the cylinder head. This
increases the likelihood of pulling or stripping the
threads in the cylinder head
- Over-tightening of a spark plug can cause
stretching of the spark plug shell and could allow
blowby to pass thru the gasket seal between the
shell and insulator. Over-tightening also results in
extremely difficult removal
3.6.2.8
Fuel Pump Module
3.6.2.8.1 Description and Working Principle
Fuel Pump Module supplies fuel to engine at system pressure. Fuel Pump Module is
mounted to fuel tank at bottom and supplies fuel to engine through hoses.
Fuel Pump module consists of Fuel Pump to generate the fuel flow and pressure
regulator to regulate the fuel pressure.
Fuel Pump
When power is supplied to fuel pump, motor in pump assembly rotates the impeller.
Impeller in turn draws the fuel from strainer and pumps the flow to generate the system pressure.
Pressure Regulator
Pressure Regulator is a diaphragm type mechanical device. Fuel flow from filter enters in the inlet of pressure
regulator. Pressure regulator regulates the fuel pressure at a set pressure by releasing the excessive fuel flow
to fuel tank.
3.6.2.8.2 Appearance & Components of Fuel Module