Honda NU50 - Fuel System Overview and Troubleshooting

f'G?\HONDA
~~) NUSO· NUSOM
4.
FUEL SYSTEM
I
~E~VICE INFORMATIO~~~
TROUBLESHOOTING
THROTTLE VALVE DISASSEMBLY
CARBURETOR REMOVAL
FLOAT/FLOAT VALVE/JETS
DISASSEMBLY
JETS/FLOAT VALVE/FLOAT
ASSEMBLY
4-1
FLOAT LEVEL INSPECTION
4-5
4-1 CARBURETOR INSTALLATION
4-6
I
4-2
THROTTLE VALVE INSTALLATION
4-6
I
4-3 REED VALVE
4-8
i
4-3 FUEL FILTER
AND TANK
4-9
10
I
4-5
I
I
~
SERVICE INFORMATION
GENERAL
U~e ciJution when working with gasoline. Always work in il well·ventilated area ;Jnd 'lway from sparks or fjarnes.
VVhen disassemblmg fuel system parts, nOtC the locations of the a·rings. Replace them with new oncs during assembly.
Bleed
air from the OJI outlet line whenever it is disconnected.
5PECIFICATlONS _
L:,enlUri diamel,.,~,~ __ r __ -:'~2~m::m::- I'
! Identifrcation number r PA13E ~
I Float lev~1
,
12.2 ± 1.0 mm (0,48 -! 0.04 in)
! Ail' screw opening
2 turns Qut
lelle spl1ed
1.800 ± 150 rpm
I
Throllie grip free play
2-6 mm 1118-1/4 in)
TOOL
Floin level Gauge
0740 I ~OO 10000
TROUBLESHOOTING
Engine cranks but won'! start
1, No fuel in lank
2, Clogged fu~1 lube
3. Clog(Jcd fllcl stri!!rW!
1. Too much fuel getting to cylinfJer
5. CI09!/cd ail' cleaner
6. F(lulty control box
lean mixture
1. Carburetor fuel jets clogged
2. Fuel Cilp vent clogg\!d
3. Clogged fuel filter
4. Fuel line kinked (}r restricted
5. Float valve faulty
6. Float level tOO low
7. Air lIent tuhe clogged
Engine Idles IO(l9hly, ~talls Of' runs poorly
1. Idle speed incorrect
2 Rtch t1)tXtllHl
3. Lean mixture
4. Clogged air cleaner
5. Inlet pipe leilking
(:i. Fltcl contaminated
Rich mixtun~
1. Faulty float vallie
2.
Float level 100 high
3. Carburetor air iets closs
Daw of Issue: Nov .. 1981
ID HONDA MOTOR CO., lTD.
35
4-1