General Information


Ordering Older S&S® Carburetor Replacement Parts
When ordering parts for older S&S carburetors, it is necessary to determine the correct style of float, needle and bowl. S&S has used two different mechanisms to connect the float to the inlet needle.

Forked Mechanism: Older style that utilizes a forked float tang, which slides into a slot in the top of the needle.

Wire Mechanism: Current style that features a needle with a wire hook which attaches to the tang of the float.

Parts of differing styles may not be used together. For example, although the carburetor bowls of the two styles look very similar, they are not interchangeable due to differences in the float retaining pin position. Some parts are no longer available for carbs with forked style mechanisms. If these parts must be replaced, the entire bowl assembly must be replaced with wire mechanism style components.

Why Is My Engine So Hard To Start?
Hot street engines have not only gotten bigger, they've also gained compression. Advances in combustion chamber design and tuning techniques have made these monsters more tolerant of pump gasoline than in the past, leaving hard starting as their main problem. 

The first step in making these beasts more manageable is to check cranking compression with a good screw-in gauge. S&S recommends 180-190 psi for street use, 200 psi for those who insist on pushing the limits. The easiest way to reduce cranking compression is to install a camshaft that closes the intake valve a little later. An engine with the recommended cranking pressure will deliver good power and throttle response but still be reasonably easy to start. Some engines, however, remain stubborn even with moderate cranking pressures. That's almost always caused by something outside the engine—a worn or binding starter or starter drive, a weak battery ,cheap or old cables, poor wiring connections, inappropriate ignition timing or overly aggressive advance curve, hydraulic lifter bleed-down, or an improperly spaced alternator rotor scraping on the crankcase, just to name a few of the culprits. Whatever the cause, there are several tricks for making a stubborn engine easier to start. 

A simple wiring change to remove the lights from the starter-ignition circuit will deliver more current to the starter. The draw back, of course, is that the rider must remember to switch the lights on. It is also possible to wire the ignition and starter circuits separately and use the handlebar "Stop-Run" switch to deactivate the ignition. With the ignition switch on and the handlebar switch in the "Stop" position, all battery current will go to the starter. That gives it more power to get the engine turning, at which point the handlebar switch can be flipped on to activate the ignition and fire the engine.

Another trick that can be extremely effective is to run a second ground cable from the negative terminal of the battery to one of the starter mounting bolts. This reduces resistance between the battery and starter, again increasing current to where it is needed. 

One last tip is to leave the throttle closed until the engine fires. Opening the throttle admits more air in to the cylinder and increases cranking compression— the last thing you want. With idle set at 1000 RPM, the engine should start with no throttle. Otherwise, pull the throttle back just far enough to get the engine to fire. Hard starting is a nuisance you shouldn't have to put up with. If your engine has 180–190 psi of cranking compression but remains hard to start, look outside the engine for the cause. If cranking compression is too high, lower your compression ratio or find a cam that closes the intake valve later.
Will The S&S Speedometer Calibrator Work For Me?
The downside to making changes in gearing or wheel sizes is that it throws off the speedometer reading. If you've got a pre–'96 bike, or custom bike using a mechanical speedometer, you have to change either transmission speedometer drive gear, or front speedometer drive unit, or sometimes even have to change out the speedometer to a different ratio to correct the speedometer reading. Even then, readings may still be only within a couple of mph of being accurate. 

That's where bikes equipped with electronic speedometers are really cool. Either stock or custom bikes can be set up with a '96 and up style electronic speedometer, and in a way that allows changing the speedometer reading without the trouble of swapping out parts to get a correct reading. The 1996–up OEM electronic speedometer itself isn't adjustable. To realize the full potential of the electronic speedometer, S&S designed a nifty little unit that plugs directly into the existing wiring and requires no tools or test equipment to use. It is makes accurately calibrating 1996–up OEM electronic speedometers a snap! It fits all Big Twin and Sportster® models originally equipped with electronic speedometers. It's also great for custom builders using a '96 and up OEM style speedometer and transmission.

The calibrator allows builders freedom to create without concern for speedometer accuracy, because the unit can be adjusted so that the speedometer reads accurately with whatever combination of gearing and tire sizes has been chosen. In most cases, it can be set so that the speedometer is accurate to within .5 percent of actual speed. What does .5% mean in mph? For simplicity sake, let's use 100mph as an example. 1%t of a 100 mph is 1 mph, and half of that one percent (.5) is one half mph. So, recalibrating your speedometer to read within one half mph of actual speed is possible. It is important to note, though, that the calibrator is designed to work with OEM components, and may not be compatible with aftermarket speedometers or transmissions. 

One notable example is that the calibrator will not work with Rev-Tech® transmissions, unless you piggy back two units together. A fairly recent development is that Harley-Davidson® changed the voltage used by the speedometer system from 12 volts to 5 volts. Sharp-eyed customers have noticed this, and our Sales and Tech departments have started getting calls asking if the S&S calibrator will work with 2004 & 2005 models. The answer is yes. S&S Test and Development department has verified that the calibrator will function at five volts and the unit has been tested on 2004 & 2005 models with good results.
How Can I Find The Year Of Manufacture?

S&S serial numbers begin with the following manufacturing year codes. Year codes coincide with S&S Cycle's fiscal year, which starts on Oct 1st of the previous calendar year. A product with serial number beginning with the letter “A” was manufactured in fiscal year 1978, between 10-01-77 and 09-31-78, or in the fiscal year 2000.

Year (First Letter) Case ID (Second Letter)
A 1978 A 2000 A Sportster
B 1979 B 2001 B Generator
C 1980 C 2002 C 4" Bore Evo
D 1981 D 2003 D Alternator/Generator
E 1982 E 2004 E 4 1/8" Bore Evo
F 1983 F 2005 K 145"
G 1984 G 2006 KN Knucklehead
H 1985 H 2007 P Twin Cam
I NOT USED I NOT USED No Second letter 3 1/2" and 3 5/8" cases
J 1986 J 2008
K 1987 K 2009
L 1988 L 2010
M 1989 M 2011
N 1990 N 2012
P 1991 P 2013
R 1992 R 2014
S 1993 S 2015
T 1994 T 2016
U 1995 U 2017
W 1996 W 2018
X 1997 X 2019
Y 1998 Y 2020
Z 1999 Z 2021


Does S&S Cycle offer plant tours?
Yes, please contact our Human resource department (ph# 608-627-1497) or email  and they will set up a time and date that works for both parties.  We are not open on weekends.

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