hey guys i have a super g with br pipes and d&m spike,i put the 76 and 31 jets in,stopped by my dealer and he said i have to put the stock 295 inter jet back in,cause when he turned the airmix screw all the way in it raised the idle instead of stalling the bike,ever heard of this? i thought for sure i would need to keep the 31 in there..the bike has a backfire every now and then on start up,and when you give it gas just a little throttle it sounds like its flooded just sucking air and hesitant cough..ill give it a try, and wait for some more suggestions thanks guys.. jim
super g jetting question
- Thread starter delly2
- Start date
its mounted horizontal,i changed the intermediat jet and its still doesnt stall out,it drops down a little bit more then before.. he said go down 1 more jet,i belive that would be a 280 285?..has anybody ever heard of going down on the inter jet so much? im gonna drive awhile and then pull the plugs and read them,i also took the vent screw out and it seems to run a bit better..im getting more decel pop which is telling me i have to much fuel off throtle which would be the inter jet correct? thanks guys..
NO WAY IN FUCKIN HELL!!!
Fuck him and his go down!!!
When it coughs does the cough from the carb itself? I bet it coughs at highway speed when you're at about 2750 RPMs.
And no way a 295 after some new pipes. 31 is the best baseline. I would think you will probably need a 32 cause I think those spikes lean it out. (please correct if I'm wrong)
Plus you can't get that much spread between the int and main jets. It leans the carb out during transition from int to main circuits.
I went thru a similar thing with my XXX when I first got it. It was Vickie that steered me into the light!
Normally I don't suggest doing a 2 jet size jump but in this case you know the 31 wasn't serving you. Go to the 32 and re-adjust the carb.
Fuck him and his go down!!!
When it coughs does the cough from the carb itself? I bet it coughs at highway speed when you're at about 2750 RPMs.
And no way a 295 after some new pipes. 31 is the best baseline. I would think you will probably need a 32 cause I think those spikes lean it out. (please correct if I'm wrong)
Plus you can't get that much spread between the int and main jets. It leans the carb out during transition from int to main circuits.
I went thru a similar thing with my XXX when I first got it. It was Vickie that steered me into the light!
Normally I don't suggest doing a 2 jet size jump but in this case you know the 31 wasn't serving you. Go to the 32 and re-adjust the carb.
Gas Man said:To adjust the carb...
Some educational reading by S&S
S&S carb adjustments
S&S Shorty Carburetor Adjustments
S&S Carb Manual
http://www.sscycle.com/modules/instruction/uploads/51-1012.pdf
For my 2 cents...
with the bike warm...
(in=clockwise/out=counter)
if your idle is low... turn it up a bit...
now spin in the accel pump screw till it seats.
now spin in your fuel/air mix screw till the motor sounds like it wants to die
now spin it back out counting 1/4 turns. Do it slowly to give the motor/carb time to adjust. Do this till the motor sound like it wants to die on this end. Now you have counted those turns and you have say 2.5 turns. Spin it back in 1.25 turns. Or middle to almost dead on each end.
Now adjust your idle to 1,000 rpms on the tach.
Now spin it out 1.5 turns
Now with a few quick stabs at the throttle see if the rpms come up fast like you would think or if it kinda hesitates then takes off. If it does hesitate then spin the accel pump out another 1/4 turn and repeat till you get what sounds good.
If that don't fix the sneeze... you can spin out the accel pump a bit more... but anything over 2.5 turns MAY mean you need a larger intermiediate jet. This is a common debate.
Then re-adjust your idle to about 1,000 RPMs. Too low and it may die. Too high and it will clunk into first gear.
Now on the plugs... to test run the bike and see if the jets are good. This can also be done before you ever screw with your jets.
Check or replace plugs.
run the bike but keep the RPMS below 2500... then don't let it idle and kill the motor, check the plugs. That is to help check the int jet.
Then take it out and run it hard... keep the RPMs up and romp on it... then on a striaght patch of road with the RPMs up high (over 3k, or even higher) kill the motor with the OFF switch. Pull the plugs and check. that is to test the main jet.
The idea here is that your int jet runs from idle to about 2750. Then the main kicks in from there out. That's why we say your run mainly on your int jet. main is only for romps.
Use this GUIDE to read your spark plugs. The basic idea is white is lean, black is rich. What you are aiming for is a nice cinnamon color to the grounding tip.
To talk jetting...
One of the most common problems is...if you are expierencing a cough at highway speed 75mph +/- RPMs at about 2750... cough thru the carb... go up on int. jet.
To jet the carb... click these links for sniplets out of the how to
(post #2, 7-8)
http://www.bigdogbiker.com/forums/how/13-how-remove-your-carb.html#post58
http://www.bigdogbiker.com/forums/how/13-how-remove-your-carb.html#post63
Of coarse once you change the jets you will need to re-adjust the carb again.
Ok I will!!! The motor is nothing more than a big air pump. I you have restricted air flow (intake) then you need to reduce the jet. If you have increased airflow (say a velosity stack) then you need more jet to maintain that magic 13.5/1 ration of air to fuel we all try to acheive. Of course if you increase the amount of intake then you need to ensure the exhaust side is getting rid of it. It's all give and take!!!
I'm only running a 29.5/72 combination (dyno proven at 13.4/1) and doing it well!!!! Thank You
lee its a g carb..ok i took the bike for a good ride and the bike seems to be running pretty good,decel pop isnt as bad as i thought..i dont have anymore coughing i also removed the vent screw,the bike seems to pull hard it gets thru the rpms real fast like it should,im gonna let the bike cool down and pull the plugs and read them..the thing i cant figure out is when i adjust the carb air mixture screw and turn it all the way in,the bike doesnt stall at all,it drops a little bit ,but no stalling,when i turn it out it raise the rpm like it should...gas this is why he is saying i should go to a smaller inter jet..im running the stock inter 295 and a 76 main jet..it pops when i start the bike,but not all the time..out of say 10 start ups maybe 1 pop.. what do u guys think?? drive it and see how the plugs look? thats what im thinking..thanks jim
Can't say I've ever seen a S&S carb not die when you turn the screw in. I would pull the carb and ensure all the passages are clean and blow it out real good. Also, check that one supply tube that has the slit in it. You will need like a 20 thousands gauge to slip in there and ensure it's clear.
You bike is quite old now and as mine is and I pull mine apart about every 6 months and find debrie in it. Just regular maintenance.
Also, where is your accelerator pump set? It should be 1-2 turns out from the stop arm. Don't just go turning it in till it stops. Use a mirror and turn it in till the screw just touchs the pump arm then turn it out. Most people shut it off while tuning cause it masks some problems. Your call!
:flag:
You bike is quite old now and as mine is and I pull mine apart about every 6 months and find debrie in it. Just regular maintenance.
Also, where is your accelerator pump set? It should be 1-2 turns out from the stop arm. Don't just go turning it in till it stops. Use a mirror and turn it in till the screw just touchs the pump arm then turn it out. Most people shut it off while tuning cause it masks some problems. Your call!
:flag:
Ok Ray... you say the spike restricts air... Then I can see the smaller int but i agree... please make sure you're turning the correct screw. Look at my pic above.
But I also stand by my judgement that you can't spread those jets too far apart like that and Ray's backs my claim. 295/72 isn't the same as a 295/76
But I also stand by my judgement that you can't spread those jets too far apart like that and Ray's backs my claim. 295/72 isn't the same as a 295/76
Black Dawg
Active Member
The intermediate jet doesn't even come on line at idle, so whatever is happening with your fuel screw is unrelated.
I believe the loud pop you hear on startup sometimes happens when you leave the fuel petcock valve open and the fuel pressure (gravity) causes a minor leak of fuel past the float needle seat which allows fuel to pool in the carb. I've tried experimenting on my bike and every time I turn the fuel off I never get the loud pop on startup. Try it.
I believe the loud pop you hear on startup sometimes happens when you leave the fuel petcock valve open and the fuel pressure (gravity) causes a minor leak of fuel past the float needle seat which allows fuel to pool in the carb. I've tried experimenting on my bike and every time I turn the fuel off I never get the loud pop on startup. Try it.
T.Byrd
Well-Known Member
If he screwed the air mixture screw all the way in and it did not kill the
engine he has other problems besides jets.There no way running a 117 with
big radius pipes that a 31 inter. jet is to much and he probably needs a 78
main jet instead of a 76 also.I would pull the air mixture screw and see what
was blocking it from closing.
engine he has other problems besides jets.There no way running a 117 with
big radius pipes that a 31 inter. jet is to much and he probably needs a 78
main jet instead of a 76 also.I would pull the air mixture screw and see what
was blocking it from closing.
No, you said the spike restricts air and recommended a bigger jet. I was just saying that a more restrictive aircleaner rates a smaller jet not a larger one!
But as Blackdawg says he has idle problems not jet problems if he's turning the proper screws. That is why I recommended pulling and cleaning the carb.
And you are right about the spread between the two jets, to much and you will have transition problems.
ok the bike ran great all day with the temp. up, but as soon as the temp dropped and it got dark out and a little chilling the bike now spits on idle at a long traffic light and sometimes stalls.. thats telling me there is to much fuel in there from the inter jet and i probobly do have to go down one more size,what do you guys think?and almost everytime i started the bike up it backfired out the exhaust,sounds like to much fuel,no? on throttle wide open from take off to like 4th gear the bikes runs great.. the carb is a g carb i upgraded from the stock e its brand new..should i try the lower inter jet? the plugs look pretty good...
Delly, again as mentioned above neither of the jets are working at idle. Did you change the carb yourself or have the dealer do it. I would check for an intake leak around the seals then ensure all the vacuum hoses were reconnected properly and there are no leaks anywhere.
And again where is the accelerator pump set to??
:flag:
ray i did it,no there are no leaks,yes all vaccumm lines reconnected..again when i had the 31 jet in there the bike would not stumble when turning in the mix screw all the way,when changed to the 295 stock inter jet it stumbled a little bit had a little ruff idle but no stalling..thats why im thinking maybe go down one more and see..the acclerater pump is set to 2 turns out from seated. 2.5 was to much fuel..2 seems to work good.. thanks jim
Well, it's probably something simple but either way the 29.5 or 31 are so close it shouldn't matter all that much.
Without having the bike sitting here in front of us it's just to hard to diagnose so hopefully you get it worked out and get some long rides in.
You might try shutting the accelerator pump off for a few days just to see whats happening. You don't really need it!
Good luck,
Ray
No, the older B and D carbs didn't even have accelerator pumps. It's fairly new to these carbs. Turn it off for a day or two and see how she runs. May have to use the enrichener to start but as soon as it does turn it off. You aren't over using it now are you? It floods and fouls plugs real quick.
Make sure your idle is set at 1000 RPM. If you see your tach lights flashing it's a warning that the idle is lower than 900 RPM.
Black Dawg
Active Member
I totally misspoke here. You DO have to readjust your fuel/air screw each time you change the int. jet.
You need to contact S&S tech and explain what your carb is doing, it should DIE if you screw the fuel/air screw all the way in. You have a defective carb.delly said:
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TCALZ06
Well-Known Member
ok here goes I had the exact same set up and I had a problem from day one at around 2500 rpms and 70 mph. I would get a popping thru the carb and had the backfire on start up sometimes.
After changing my air cleaner set up to the new S&S dual intake the problem at 2500 got a lot worse. Since the dealer had just f'd up my bike at the 5k service I decided to go buy several jets and see what I could do.
These dealers are pathetic. The dealer had lied and left the stock jets in so I changed the intermediate jet to the .031 and went for a ride. My bike runs great now and I have not had a problem in the last 100 miles.
I did the carb adj per the S&S instruction sheet. I also screwed in the accelerator pump screw and the air fuel mixture and I couldn't get the bike to run like crap so i left it at the base settings.
I'm going to check my mileage and then maybe change the main jet to the 78 and see how it runs but right now I have picked up a noticeable amount down low
After changing my air cleaner set up to the new S&S dual intake the problem at 2500 got a lot worse. Since the dealer had just f'd up my bike at the 5k service I decided to go buy several jets and see what I could do.
These dealers are pathetic. The dealer had lied and left the stock jets in so I changed the intermediate jet to the .031 and went for a ride. My bike runs great now and I have not had a problem in the last 100 miles.
I did the carb adj per the S&S instruction sheet. I also screwed in the accelerator pump screw and the air fuel mixture and I couldn't get the bike to run like crap so i left it at the base settings.
I'm going to check my mileage and then maybe change the main jet to the 78 and see how it runs but right now I have picked up a noticeable amount down low