CarbTuningGuide

CarbTuningGuide
S&S® Cycle, inc.
6- Overflow Tube Fitting
7- Fuel Inlet
8- Bowl Vent Hole
9- Bowl Plug
3
2
10
1
Tuning Guide
11
8
4
Super E & G Carburetor
13
5
1- Idle Speed Screw
2- Idle Mixture Screw
3- Accelerator Pump Adjustment Screw
4- Enrichment Device
5- Serial Number
12
6
7
9
10- Accelerator Pump Pushrod
11- Intermediate Jet
12- Main Jet
13- Main Jet Air Bleed
14- Auxiliary Bowl Vent Plug
14
Quick Tuning Steps
1-
2-
3-
4-
5-
Verify carburetor is set to stock settings:
a- Idle Mixture Screw, 11/4 turns from lightly seated.
b- Idle Speed Screw, ½ turn clockwise from
engagement point.
c- Accelerator Adjustment Screw, two turns
counter-clockwise from seated.
Start bike, bring to operating temperature.
Set Idle Speed Adjusting Screw, clockwise to increase
rpm, counter-clockwise to decrease rpm. Idle rpm range
should be 950 to 1050 rpms.
Adjust idle mixture by turning Idle Mixture Screw slowly
clockwise until the engine runs poorly. Slowly turn the
screw counter-clockwise until it runs smoothly—if you
go too far the engine will start to stumble.
With engine idling, turn Accelerator Adjustment Screw
clockwise until it lightly seats. Snap throttle open—
engine should stumble. Turn screw counter-clockwise ¼
or ½ of a turn at a time, until engine responds to throttle
twist with smooth, quick response.
6-
7-
8-
Ride motorcycle in various rpm ranges, and then try to
maintain a consistent 40- to 50-mph. If the engine is
popping or sneezing in the air cleaner it can indicate a
lean condition. If you notice stumbling or sputtering it
can indicate a rich condition.
Low rpm operation is controlled by the intermediate
jet (#11) if coughing or popping is experienced below
approximately 3000 rpm’s the intermediate jet must be
replaced with a larger sized (richer) jet. If the engine is
sluggish or does not want to idle smoothly a smaller
(leaner) intermediate jet needs to be installed. Always
readjust the idle mixture (#2) and idle speed (#1) screws
after making a jet change.
To test the Main Jet, do a roll-on from 50-mph to 70-mph
in 3rd gear. If the engine back fires or breaks up in the
carb, increase the Main Jet size .004”. If the engine is flat
or will not accelerate, decrease the Main Jet by .004”.
9-
Since 2004 S&S Shorty carbs have been fitted with an
adjustable main jet air bleed (#13). Changing this jet to
one of a larger size will delay the signal to the main jet,
therefore aiding with high speed tuning as described
in step 8. This also aides with tuning an engine that is
fitted with an exhaust system that is not intended for
high performance.
10- NOTE: Drag or straight pipes can prevent you from
obtaining optimum carburetor performance.
11- If the S&S teardrop air cleaner is being replaced with an
aftermarket air cleaner be sure to remove the auxiliary
bowl vent screw (#14). Never use a velocity stack on a
street driven motorcycle! Poor throttle response will be
experienced.
12- Always be sure to attach the hose to the overflow tube
fitting (#6) and route it towards the back of the engine.
S&S® Cycle, Inc.
235 Causeway Blvd.
La Crosse, WI 54603
www.sscycle.com
For more information or to find the dealer closest
to you, please visit our website.
© S&S Cycle, Inc. 2008
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