Poor Performance At Low And Idle Speeds - Honda CH250 Elite 1986 Service Manual

TROUBLESHOOTING
POOR PERFORMANCE AT LOW AND IDLE SPEEDS
Probable cause
1. Check timing 3·8) INCORRECT----------t ...
(1)
Faulty COl unit
(2)
Faulty pulse generator
for leaking intake pipe
2.
3.
carburetor
adjustment
CORRECT
NOT LEAKING
!
screw INCORRECT - - - - - - - - - -......
~ 1)
Fuel air mixture too rich
(Turn screw in)'
(2)
Fuel air mixture too lean (Turn
screw out)
LEAKING - - - - - - - - - - -....
{11
Deteriorated O-ring
(2)
Loose carburetor •
(31
Damaged insulator rubber
(4)
Air leaking past intake pipe
vacuum joint
4, Perform spark test
GOOD SPARK
1
5.
Check the air cut-off valve
4-6)
CORRECT
WEAK OR INTERMITTENT SPARK_Ill Faulty, carbon or wet fouled spark
plug
(2)
Faulty COl unit
(3)
Faulty pulse generator
(4)
Faulty ignition coil
(5)
Broken <)r shorted spark plug wire
(6)
Faulty ignition switch
INI:':ORRECT ------,........-'---........ Faulty
,nT rIIT.nTT
POOR PERFORMANCE AT HIGH SPEED
Probable cause
CORRECT
t
2.
Check valve clearance
CORRECT
t
3. Disconnect fuel tube at
auto fuel valve
FUEL FLOWS FREELY
!
4.
Remove carburetor and check
for clogged jet
1. Check ignition
NOT CLC)G(,ED
(page 3·8)
INCORRECT---------.....
(1)
Faulty COl unit
(2)
Faulty pulse generator
INCORRECT---------__.... ..
(1)
Improper valve adjust-
ment
(2)
Worn valve seat
FUEL FLOW RESTRICTED------1 ......
(1)
No fuel in fuel tank
(2)
Clogged fuel tube or filter
(3)
Clogged fuel tank cap
breather hole
(4)
Faulty auto fuel valve
C L O G G E D - - - - - - - - - -...... Clean
5.
6.
valve
CORRECT
valve spring tension
NOT WEAKENED
INCORRECT - - - - - - - - - - - 1 ....... Cam sprocket aligning marks not
aligned
WEAK - - - - - - - - - - - -..... Faulty spring