super g jetting question

[lee]

I agree you may have something wrong with the carb if it doesn't stutter when turning the mixture screw all the way in - you should be getting any fuel. Also remember that after first adjusting your idle speed and mixture, you will have to do it again when the engine gets hot. You say you just moved from an E to a G - this might be a stupid question but presumably your dealer removed the restrictor plates and replaced the intake manifold? still not sure even this would cause the idling issues you have.

 

[Raywood]

this might be a stupid question but presumably your dealer removed the restrictor plates and replaced the intake manifold? still not sure even this would cause the idling issues you have.

Good point Lee, since he did it himself! :flag:

 

[dogvet]

..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

If you turn your mixture screw all the way in and the bike doesn't die, then somebody turned the screw in too far and fucked up the seat for the mixture screw. Nothing you can do for that but replace the carb.

If you remove the mixture screw, you'll probably see a deformation of the taper where it contacts the seat. If you look in the throat of the carb at the top of the venturi you'll see the hole the mixture screw lives in and 4 transfer ports behide the butterfly. If you can see cracks or deformation of this hole or can catch the edge of the hole with a fingernail, your carb is done being a carb and is now ready to become a paperweight or a memento to put on a shelf of shame.

NEVER turn the mixture screw beynd a "light" contact with the seat! I've seen many carbs have to be junked because of this!:down:

 

[barhopper]

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

Gas, I run a 31/84. Have a stumble I would say from 1800 to 2500 or so(xxx carb). Bike runs awesome when I am running through the gears, but to just cruise at lets say 2000 rpm, the bike jerks some, not smooth. Do you think my main is to high? I dont think my main is on at this point. Is my spread to far apart between jets? I had it dyno'd and those are the jets they put in it. The motor is ported, different ign, cam, MM pipes, k&n filter. ect. Maybe getting 30 mpg now. I have not taken out the vent plug yet, will do this weekend. Everyone else is and it seems to do something.

 

[Gas Man]

Gas, I run a 31/84. Have a stumble I would say from 1800 to 2500 or so(xxx carb). Bike runs awesome when I am running through the gears, but to just cruise at lets say 2000 rpm, the bike jerks some, not smooth. Do you think my main is to high? I dont think my main is on at this point. Is my spread to far apart between jets? I had it dyno'd and those are the jets they put in it. The motor is ported, different ign, cam, MM pipes, k&n filter. ect. Maybe getting 30 mpg now. I have not taken out the vent plug yet, will do this weekend. Everyone else is and it seems to do something.

Barhopper... I would say yes, that stumble is due to the jet spread. The carb is having problems transitioning. I thought you had more work done to yours. I would say you need to check your plugs both below 2500 and above. Where you kill the bike under both circumstances. I guess you need to go bigger int or smaller main or both depending on what the plugs tell you.

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

I was going to say something but Mr Vet stepped in first

If you turn your mixture screw all the way in and the bike doesn't die, then somebody turned the screw in too far and fucked up the seat for the mixture screw. Nothing you can do for that but replace the carb.

If you remove the mixture screw, you'll probably see a deformation of the taper where it contacts the seat. If you look in the throat of the carb at the top of the venturi you'll see the hole the mixture screw lives in and 4 transfer ports behide the butterfly. If you can see cracks or deformation of this hole or can catch the edge of the hole with a fingernail, your carb is done being a carb and is now ready to become a paperweight or a memento to put on a shelf of shame.

NEVER turn the mixture screw beynd a "light" contact with the seat! I've seen many carbs have to be junked because of this!:down:

I can't figure out why you ever would be able to seat the mixture screw. The only one you do that to is the accell pump.

And as Vet said... "LIGHTLY"

 

[barhopper]

Barhopper... I would say yes, that stumble is due to the jet spread. The carb is having problems transitioning. I thought you had more work done to yours.

I have larger valves also. 650 woods cam, I will put in a smaller main jet to see what it does. No one here is running a 84 main. may be to large, but it runs great when on it. Thanks.

 

[delly2]

dogvet, i took the screw out and there is nothing wrong with it,it has a nice sharp point to it..this problem im having seems to be fuel,when idleing sometimes at a long traffic light it coughs out the carb,or when i go to take off it coughs then goes,wide open throttle its fine,during the day when it was 80 out it ran excellent,as soon as the temp dropped it idled like shit between 1k and 1.5k rpms and after that its fine.. dogvet i have a 295 inter and 76 main think i should try the next lower inter jet? will it do anything bad to the motor? thanks jim

 

[delly2]

sorry guys when i said turn in the mixture screw ALL THE WAY ,i ment till it seats i never force it, just wanted to state that as to some may be thinging i forced it all the way down,sorry ..jim

 

[lee]

all good info from the boys Delly - what about the restrictor plates? did you remove them? if not they will contribute to you running lean - with a G, .295 sounds too small to me and I wouldn't have thought the temperature drop later on in the day would should make that much of a noticeable difference

 

[lee]

I have larger valves also. 650 woods cam, I will put in a smaller main jet to see what it does. No one here is running a 84 main. may be to large, but it runs great when on it. Thanks.

84 sounds quite high to me but obviously everybody's set up is different - definitely remove the bowl vent screw - just out of interest what size valves have you got and are the intake and exhaust valves the same size? apologies if I'm jacking the thread with this question

 

[barhopper]

I will look it up lee.

 

[Black Dawg]

Ok, if it's not the fuel screw the only other thing I can think of is a badly leaking, or set too high, float needle. That might account for your loud pop at start up and some flooding while the bike is at idle. Full throttle the needle seat opens all the way and it would be fine. This would also explain in all probability why when you screw your fuel screw all the way in (max lean) the engine still runs.

 

[delly2]

the plugs now are showing on the rich side,and they are the exact same..im gonna try the .28 inter jet ..and ill let you guys no what happens..jim

 

[Black Dawg]

the plugs now are showing on the rich side,and they are the exact same..im gonna try the .28 inter jet ..and ill let you guys no what happens..jim

You're going to end up burning an exhaust valve or worse if you keep jetting leaner.

You're intermediate jet IS NOT CAUSING YOUR PROBLEM.

 

[lee]

sorry - my previous post said the restrictors will lean it out - that is bollocks of course - they will restrict the air flow - my bad

 

[lee]

thanks Sul - you learn something every day

 

[Gas Man]

What is the RPM of the bike when you shut it down and how you rode it right before will mask what is going on when reading plugs. If you were hot rodding it then shut it down.. then the rich look could be the main plug running rich.

or like Sul said... something else. I'm wondering about your breathers... are they both breathing into the air cleaner backing plate and intake?

 

[gbinno]

Just to throw in my two sense. I'm bought a Chromed S&S "G" with 78 and 295 jets to complement the chromed intake and the engine runs great. I also have a D&M spike air cleaner and a custom made Martin Bros 2 into 1 pipe. When I change to my other pipe , an Arlen Ness 2 into 2 I get a little popping from the pipes when I let off the throttle between shifts. My old OEM S&S "G" had 70 and 295 jets, ran exactly the same way. Go figure. The Chromed "G" has Booster Kit to improve fuel emulsion (breaks up fuel into a fine mist for better cylinder filling).

 

[delly2]

ok, something i should of checked before putting all this up on here,i decided to pull the airmixture screw out and put the one from my e carb in,and guess what the bike shuts down now when i turn the screw in to the seated postion,go figure,i checked the other screw and without really looking at it i would have never noticed but there was a little of that orange crap inbetween the middle of the screw between the trheads and it wasnt allowing me to screw it in to the seated position,thats why the bike wouldnt shut down like its suppose to..im really sorry guys for putting you all on a wild goose chase... so instead of changing the jet down one i tried to tune it again with the 295 jet in there,and i have the same problem,kinda it ran well,but as temp came down it coughed out the carb on take off a few times and the idle dropped down some,also i have real bad decel popping and crackling now worse then before..so do you guys think i should go back to the 31 inter jet now and try to tune it in? thats what im gonna try tommorrow..any other options or do this first? again i appologize for not checking this air mix screw sooner ...thanks jim

 

[Black Dawg]

Definitely install the richer intermediate jet. That's why it's sneezing out the carb.