S&S Super G Update (Jetting)

[Legend Rider]

A couple of weeks ago I asked for advice on some issues I was having with my bike popping, backfiring, surging, etc. Thanks for all the input, still having some issues.

I took out the immediate/slow jet and the main jet on the S&S G with a D&M Power Flow Air Filter, V&H Big Radius Pipes (long) and what was in there was a 031 intermediate and a 070 main jet. The advice I receive was to go to a 032 intermediate and to 076 main jet. I did this set the idle mixture screw to 1 1/2 turns and the accelerator pump to 2 turns. Went for a ride, the bike was still popping, etc,. I adjusted the idle mixture screw until the popping stop and I was at 2 1/4 turns out.

The bike was surging/hesitating though out the RPM range. Went back and change out the main jet to a 078. I readjusted the idle mixture screw back to 1 1/2 turns and the accelerator pump screw was about the same.

The bike still had some hesitation in the lower gears and was still popping on deceleration, adjusted the air mixture screw, again went to 2 1/4 turns before the bike ran smoothly, but with a small amount of hesitation/surge in 2nd, 3rd and 4th gears. The hesitation/surge lasted for only a split second and when the engine caught up it was off to the races.

I have check for air leaks around the the carb and the manifold with some Carb Cleaner. Nothing

Do I need to go up to a 033 on the intermediate jet to eliminated the hesitation/surge. Will this help in getting the idle mixture screw adjustment between 1 1/4 to 1 3/4 turns like S&S recommends. Also the bike is a bitch to start in the mornings and occasion even when its hot. Would this be related to the jetting of the carb or more of a electronic ignition problem as far as the timing of the bike or both.


Thanks - Glenn

Ed, if you see this, let me know what you have done to your ride. Have you rejetted, were is your idle mixture screw set at?? Thanks

[Ricky-D]

When you say "popping" I think you are referring to the carburetor.

With all things being correct and still popping I think the general consensus is that the reason for that would be a lean gas/air mixture.

An accelerator pump is designed also to help in that particular area but it's a bit too slow to stop the problem.

I would recommend a sweeter slow jet (intermediate in your carburetor) to enrich the mixture off idle. Ought to stop the popping.

***

[Merlin Hawaii]

Originally Posted by Legend Rider

Do I need to go up to a 033 on the intermediate jet to eliminated the hesitation/surge. Will this help in getting the idle mixture screw adjustment between 1 1/4 to 1 3/4 turns like S&S recommends.

If you're midway between a too rich stumble and a too lean stumble at 2 1/4 turns out,

Then, yes, go up a size on the intermediate jet

Turn off the accelerator pump until you get the intermediate and main circits dialed in

[Merlin Hawaii]

Originally Posted by Legend Rider

Also the bike is a bitch to start in the mornings and occasion even when its hot. Would this be related to the jetting of the carb or more of a electronic ignition problem as far as the timing of the bike or both.

Probably a simple carb tuning issue.

[maddmaxxx]

-hi mr legend; ive got a 113 ci engine...w/ 10.8;1 cr and a 630 lift cam and dart 'port job'

-the 'g' carb ive got iz happy w/ 33 intermediate and 78 main [just under 1 and 3/4 out]... and consistent cinamin looking plugs

-you must shut off your acc pump to dial-in your int screw and make sure your air filter iz in good shape

-dont worry about your mainjet yeti...concentrate on your int jet

-there should be NO hesitation at all w/ the 'e' or 'g' carbs


-and i always check the manifold seals like you did...good habit , #1 problem i encounter

-what size motor and cam do you have guy ???



-

[Legend Rider]

Thanks for the replies. To clarify what I was describing about the popping; the popping, or backfiring was occurring through the pipes, not the carb and it was happening on the deceleration mainly in 2nd, 3rd, and 4th gears. Now on occasion when trying to start the bike a backfire would occur through the carb, cold or hot.

When adjusting the air mixture screw, I would turn off the accelerator pump by turning the screw clockwise until seated. I would start a 1 1/2 turns out and began there. I would then turn the air mixture screw in (clockwise) until the motor began to idle very rough. This would happen around 1 1/4 turns out. Than I would back the screw out until the motor began to increase in RPM's, than split that distance in half and I end up at 2 1/4 turns out. Is this the right way to do this?

After this I would adjust the accelerator pump by twisting the throlle until the response was smooth. I'm 1/34 turns out on the accelerator pump currently.

I just got back from a ride into town about 70 miles round trip, bike runs very good, just have the hesitation/surge in the lower gears. That is for example I'm in 3rd gear, I twist the throttle to wide open I get a hesitation, a surge, or a very short "O'my god" and she is off building RPM's and speed.

Merlin, its a stock 111 S&S Sidewinder motor and the air cleaner is less than a year old. The bike has been to 3 shops already for this problem, no one seems able to get it right. Main Jets have been change every time, I don't know if the intermediate jet have been change or not until I just change them. There is no shop near here with a dyno that I know of. The last place that work on it was Jack's Custom, I expect that's were the 070 main was put in, but the bike never run right after they mess with it either.

With you guys helping, I will get it right, thanks - Glenn

[pec]

here you go right from S&S!


1. Start engine and run until slightly warm
(approximately 1 to 2 minutes).
2. Turn RPM adjustment screw to obtain idle of
approximately 1000 RPM.
3. Turn idle mixture screw clockwise, slowly leaning
mixture until engine starts to die. Next, turn screw
counterclockwise, slowly richening mixture, until
engine RPM fall off. Mixture adjustment is correct
when screw is positioned about halfway between
these points, or approximately 1⁄4 to 1⁄2 turn out from
lean side of adjustment range.
NOTE: Turning screw out (counterclockwise) makes idle mixture
richer. Turning screw in (clockwise) makes mixture leaner.
Normally, correctly adjusted screw will be between 11⁄4 and 13⁄4
turns out from bottom if intermediate jet size is correct. Note
that mixture screw must be adjusted according to Step 3 above.
Do not leave screw at initial 11⁄2 turn setting without fine tuning.
4. After initial idle mixture adjustment, reset engine
idle to approximately 1000 RPM. Lower idle speed
can cause hard starting, poor throttle response,
erratic idle and unnecessary engine wear.
5. After engine has reached normal operating
temperature, repeat Steps 3 and 4.
IDLE CIRCUIT NOTES:
l If idle adjustments are made before engine is fully warmed,
idle mixture will be rich when engine reaches operating
temperature. This is especially true for engines with aluminum
cylinders such as Harley-Davidson® Evolution® and Twin Cam
88®. If ambient temperature is below 60 degrees, engine may
require 10-15 minutes of normal riding to reach operating
temperature.
l Whenever intermediate jet change is made, idle mixture
screw must be readjusted.
l If the idle mixture screw is more than 13⁄4 turns out after idle
mixture is correctly adjusted, it is a fairly good indication that
the intermediate jet may be too small and should be
changed to the next larger size. If the idle mixture screw
ends up less than 11⁄4 turn out, the intermediate jet may need
to be changed to the next smaller size. Be aware that idle
mixture screw adjustment can be effected by other factors,
but can quite often indicate rich or lean intermediate jetting.
l If idle mixture screw is turned completely in, engine should
not run at idle. If engine continues to run at idle with idle
mixture screw seated, recheck initial setting of idle speed
screw, and make sure enrichment plunger is seated. If the
engine still runs at idle with the idle mixture screw turned all
the way in, contact S&S® Technical Services Department.

[Merlin Hawaii]

Originally Posted by Legend Rider

the popping, or backfiring was occurring through the pipes, not the carb and it was happening on the deceleration mainly in 2nd, 3rd, and 4th gears.

Now on occasion when trying to start the bike a backfire would occur through the carb, cold or hot.

Backfiring/popping on deacceleration is a normal phenomenon - don't worry about that.

Backfiring, coughing, or sneezing through the carb, however, is a sign of a too lean A/F mix.

[Merlin Hawaii]

Originally Posted by Legend Rider

I would start a 1 1/2 turns out and began there. I would then turn the air mixture screw in (clockwise) until the motor began to idle very rough. This would happen around 1 1/4 turns out. Than I would back the screw out until the motor began to increase in RPM's, than split that distance in half and I end up at 2 1/4 turns out. Is this the right way to do this?

Not exactly

Turn the A/F screw in until it starts to stumble (too lean)

Then turn it out until it starts to stumble again (too rich)

Then set it midway between those two points

And you want to have that midway way point somewhere between 1 1/4 and 1 3/4 turns out from GENTLY seated

So from what you've described - if you're 2 1/4 turns out, and still haven't found the too rich stumble

Then you should try to go up a size on the intermediate jet

[Merlin Hawaii]

Originally Posted by Legend Rider

I'm 1/34 turns out on the accelerator pump currently.


Merlin, its a stock 111 S&S Sidewinder motor and the air cleaner is less than a year old. The bike has been to 3 shops already for this problem, no one seems able to get it right. Main Jets have been change every time, I don't know if the intermediate jet have been change or not until I just change them. There is no shop near here with a dyno that I know of. The last place that work on it was Jack's Custom, I expect that's were the 070 main was put in, but the bike never run right after they mess with it either.

With you guys helping, I will get it right, thanks - Glenn

1 3/4 turns out on the acc. pump is about where I am on my bike

But turn off the acc. pump for the time being - until you get the intermediate and main circuits dialed in

Intermediate jetting is much more impt for street riding because those are the throttle openings where most of our riding is done

Intermediate jetting also has an effect on the main jetting, so you have to get the intermediate dialed in first

You don't need a dyno to tune a carb (unless you are racing competitively). A good tuner can get it dialed in just right by ear



.

[Merlin Hawaii]

I just went back and read your questions in the previous thread

You were asking pretty much the exact same questions

And getting pretty much the exact same answers

Deja Vu?

[gypsy chopper]

do any adjusting with the engine hot.

hot is the point where it starts to very slightly idle up, by itself, after you first start it cold. this is your condition when you are riding the bike, and your adjustment will be more precise if done at operating temp. unless you only ride 5 miles at a time. 1-2 minutes warm up isnt enough for me. it might be close, but it aint it.