Carburetor Tuning

[603sporty]

Hi all

I have a 1987 Harley Davidson Sportster 1100 that I've done a little bit of motor work to. I am running a S&S Super E carb with a Thunderheader 2 to 1, Andrew's V8 cams, and a Daytona Twin Tec 1005 ignition system set for typical street applications. I have to re jet the carb to get the most of my set up. Right now I have the set baseline jets installed for basic tuning with understanding that this is NOT the correct jetting for the application. Jet sizes are as follows;
Main - .072"
Intermediate - .0925"

Anything helps
Thanks

[JBinNC]

I think you will find that the .072 main jet is too big, and you may end up with a main jet as small as .066. You mistyped the intermediate jet size, I'm sure you meant .0295. Depending on how the pipes affect the tune, you may have to go up or down one jet size on the intermediate. Don't forget that you can tune the main air bleed as well.

And, AS ALWAYS, check the float level before any tuning.

Jim

[docmel]

SS has a great tuning video and tuning tips. Its easy to just start changing out jets, etc, and not get what you want

SS has great reads and vids on what to change based upon symptoms. I would start with running what you have now and then start adjusting as needed based on SS inputs, or at least the symptoms that you are experiencing.

All bikes have dif tunes based upon mech condition, mods, altitude, etc. No one set up really fits all

I have also found many tend to blow off adjusting the accel pump.

Get a good basic understanding on what jets come into play and when, and when the accell pump plays into it. It will keep you from changing things out thats not needed, and focus on what does

Remember that the carb is just a part of getting the most out of what you have. Timing plays in as well

Last is your cam: Allot of folks just put them in and hope for the best. Remember that the cam is the HEART of any engine, and anything plugged into it should fit the cam profile, or be adjusted as such

[SpinCityMoto]

Original post lacks temp and altitude. So nobody can give windows of jetting


Air bleed is only on the newer Super E’s

Always adjust the pumper last. On any carb. This avoids false feedback. Every jet setup needs to started with a low speed jet and idle adjustment on a warm motor. All the time, every time, the rest plays off this. Pumper is last.

Cams and ignitions don’t affect jetting. Intake or filters may.

Follow the manual with the authentic jets. Do not buy eBay or Amazon jets. Or any parts for carbs. They sell a kit of low and high sets. You should be on the low set. (Leaner. Small numbers set)

The Super E is pretty easy to setup and once running well everything goes smoothly. Many don’t have well jetted bikes.

Test for intake leaks. Not sure if similar to BT, but a common issue on pans and shovels and will cause frustration.