GAS GAS EC 125 - 2003 Service Manual page 42

Check the condition of the spark plug, make sure the ingnition timing
is correct, service the air cleaner element, decarbonize the muffler
If you machine has run properly at a certain track in the past and
then starts running poorly with the same carb settings, the problem
is almost certain to be elsewhere; changing the carb settings in such
a case would probably be a waste of time.
Condition of spark plug
Correct Insulator dry and light tan color
Too lean Insulator is whitish
Too rich Insulator is wet, black and
sooty
- Set the carburetor so that the engine delivers satisfactory power
at any throttle opening.
- If the air-fuel mixture is too lean, the engine tends to overheat and
may seize up; on the other hand, if it is too rich, the spark plug easily
gets wet, thus causing richness, the spark plug easily gets wet, thus
causing misfires. The proper strength of the mixture varies depending
on atmospheric conditions (pressure, humidity, and temperature).
Taking these conditions into consideration, adjust the carburetor
settings properly
Standard Settings
FUEL UNLEADED
Throttle valve cutaway
Slow jet
Jet needle
Main Jet
Replace the main jet with one
step larger
Replace the main jet wit one
step smaller
LEADED
7 7
38 35
N1EC N1ED
185 160
EC 2003 -
Correction factors:
(For changes in altitude and temperature).
1. Find your correction factor to adjust the carburetor.
EXAMPLE: 1000 meters (3200 ft) altitude with an air temperature
of 35º C (95ºF). The correction factor is 0.94 (see dotted line for the
example.
2. Using your correction factor, select the correct slow jet and main
jet.
Example: For a correction factor of 0.94, multiply the jet size by that
number.
Slow jet: # 50 x 0.94 = #47
Chiclé principal: # 162 x 0.94 = # 1
3. Find your correction factor on the Jet Needle/Air Screw chart and
change the jet needle clip position and air screw opening as indicated.
Example: For correction factor of 0.94, raise the needle clip one
position and turn out the air screw one extra turn.
- Jet needle clip setting: 3rd groove from top minus 1 - 2nd groove.
- Air screw opening: 1 1/2 + 1 turn = 2 1/2 turns out.
For the following recommendations to be accurate, you must
use the standard settings as a base-line. Also don´t change any
of the settings until you´ve determined what changes are
necessary. All specifications are based on the use of the
specified fuel and oil.
104
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NOTE