Carburetor Tuning; Principles Of Carburetor Tuning - Suzuki RM 250 2003 Owner's Service Manual

Table of Contents

Advertisement

CARBURETOR TUNING

The carburetion of your motorcycle was carefully
selected after extensive testing. You will find that
the carburetion will function smoothly under many
varied operating conditions. For best results we rec-
ommend that the adjustments and carburetion jet-
ting be left "as is" from the factory.
Some riders may operate their motorcycle under
extreme operating conditions such as; very high
altitudes or extreme cold and hot temperatures. In
these circumstances the jetting of the carburetor or
other adjustments may need to be altered slightly.
Riders who are not familiar with the operation and
jetting procedures of the KEIHIN carburetor should
have their local authorized Suzuki dealer perform
these alterations. Mechanically experienced riders
can alter the carburetor settings based on the fol-
lowing information and specifications.
Carburetor Specifications
Bore
Main jet
Jet needle
Cut-away
Slow jet
Air screw
Power jet
Float height
Setting parts
Main jet
#168
Main jet
#175
Jet needle
NECH
39 mm
#172
NEDH-4th
#7
#50
1 and 1/2 turns out
#55
6.5 mm (0.26 in)
Parts No.
09491-33010
09491-35009
13383-37FC0
PRINCIPLES OF CARBURETOR
TUNING
CARBURETOR COMPONENTS AND FUNC-
TIONS
The carburetor consists of a number of parts as
shown below. The asterisk (*) marked parts are pre-
cisely machined, which meter the intake air (oxy-
gen) and fuel so that the air/fuel mixture ratio is
controlled accurately. They can be divided by three
operation-related groups; pilot (slow) system, inter-
mediate system and main system, and they achieve
their functions in each corresponding throttle open-
ing range. It is necessary to have a full understand-
ing of them for proper carburetor tuning.
3
4
14
6
13
10
12
1.
Top cap
2.
Spring
3.
* Clip
4.
* Jet needle
5.
Throttle valve
6.
Starter knob
7.
Throttle stop screw
8.
* Air screw
FUEL SYSTEM
1
5
15
2
7
9
11
8
9. * Main jet
10. * Slow jet
11.
Needle valve ass'y
12.
Float
13.
Power jet
14.
Solenoid
15.
Throttle position sensor
9-3

Advertisement

Table of Contents
loading

Table of Contents