Hisun HS700UTV-4, Maintenance Handbook

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ENGINE MANAGEMENT SYSTEM
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deposits, clean with wire brush, taking care
not to injure the electrode or the
insulator tip
DO :
Regap spark plugs to the exact
measurement specified by the engine
-Too wide a gap could cause the plug to
misfire(higher required ignition voltage).
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 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
Fuel Pump Module
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.