Trouble Shoottng; 1 -1 Starting Difficulties - Robin EY14 Service Manual

11. TROUBLE SHOOTING
For a satisfactory starting and running conditions of a gasoling engine, the following three
requirements must be met:
1. The cylinder filled with
a proper fuel-air mixture.
2. An appropriate compression
in
the cylinder.
3. Good spark at c o r r e c t t i m e to ignite the mixture.
c\
If all three requirements
are
not met simultaneously, an engine can not be started.
There
are also other factors such as heavy load
at
starting and too long exhaust pipe causing high
back
pressure, which contribute to hard starting. The most common
causes
of engine
troubles are given below.
11-1 STARTING DIFFICULTIES
11-1-1 FUEL SYSTEM
1)
'No gasoline in fuel tank, or fuel cock closed.
2) Carburetor insufficiently choked, especially when engine is cold.
3) Water, dirt or
gum in gasoline hindering flow of fuel to carburetor.
4)
Inferior or poor grade gasoline not vaporizing satisfactorily to produce correct fuel mixture.
5) Needle valve in carburetor held open by
dirt or gum. This condition
is ascertained by
continuous fuel drip from the carburetor during idling.
Sometimes, this trouble is remedied by lightly tapping
t h e
float chamber with a screw driver
handle or the like.
6 )
Due to carburetor flooding, too much fuel introduced in the cylinder through cranking,
making
t h e
mixture too rich to
be
ignited.
When
this
happens, remove spark plug and turn
t h e
engine over several times with starting
pulley to evacuate over-rich mixture through the plug hole. Keep carburetor choke open
during this operation. Dry spark plug thoroughly and reinstall, and try to start again.
n
11-1-2
COMPRESSION
SYSTEM
When the fuel system and the ignition system are eliminated
as
t h e
cause of starting difficulties
and loss of power, the following are to be checked for possible
lack
of compression.
1)
Cylinder dry after long interruption of operation.
2) Loose or broken spark plug. In this case, a hissing noise is audible, during cranking, made by
3)
Damaged
head
gasket or slack cylinder head tightening.
A
similar hissing noise is produced
4) Tappet clearance incorrect. (See "6-3-8, 4) Tappet Adjustment'!)
If
t h e
compression
is
not recovered after correcting the above faults,
t h e
engine must
be
partly
dismantled and
t h e
foliowing m u s t
be checked.
1) Valve stuck open due to carbon or gum
OR
valve stem.
2)
Piston rings stuck in piston due to carbon accumulation. Remove pistor! and connecting rod
escaping mixture gas in compression stroke.
during compression stroke.
from engine and clean, correct or replace parts.
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