Announcement

Collapse
No announcement yet.

emission jets and air screws

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    emission jets and air screws

    I own a 1978 GS1000C. I have owned it for 20 years. This past winter I made the mistake of leaving ethanol laced fuel in the bike. The petcock that has worked perfectly 20 years, decided it was time to leak. This kept fuel in the carbs.This spring when I tried to start it, it coughed and gagged finally running on 2. I knew immediately what was wrong as this happened to me on another bike, a GT550
    So I pulled the carbs and cleaned all the coagulated funk out of the mains a severely clogged pilot jets and all the passage ways. I am ready to put the carbs back on and I have 2 very pointed questions.
    The emission jets on the carb bottom were removed when I first got the bike. I didn't think I could do a good job of cleaning the carbs with those in place.. I checked these emission jets before I pulled them out this time and they were all over the place, ranging from 3/4 to 2 1/8 turns out, Equally, the air screws were all over the place as well. They ranged from 1/2 to 3 1/2
    So my question are, is there a base line / ball park setting for the emission jets. and how much effect do they have on the actual tuning of the carbs? Also is there a base setting for the air screws?

    I should mention the bike had a dyno-jet stage 3 installed about 7 years ago. It was 'professionally' tuned at that time. Hasn't run all that well since. Also running pods Bike has 26,560 actual miles and has never been opened.

    Thanks
    Tags: None
    #2
    this is what you need..

    http://members.dslextreme.com/users/bikecliff/images/vm_carb_rebuild.pdf


    Bottom pilot scrrews are at 3/4 to 7/8 out and left alone after that. Side mixture screws are where the adjustments are made and set at about 2 out as the starting point. youll probably get the best performance with them at around 1 1/4 to 1 3/8 out though.
    Last edited by chuck hahn; 06-29-2015, 08:49 PM.
    MY BIKES..1977 GS 750 B, 1978 GS 1000 C (X2)
    1978 GS 1000 E, 1979 GS 1000 S, 1973 Yamaha TX 750, 1977 Kawasaki KZ 650B1, 1975 Honda GL1000 Goldwing, 1983 CB 650SC Nighthawk, 1972 Honda CB 350K4, 74 Honda CB550

    NEVER SNEAK UP ON A SLEEPING DOG..NOT EVEN YOUR OWN.


    I would rather trust my bike to a "QUACK" that KNOWS how to fix it rather than a book worm that THINKS HE KNOWS how to fix it.

    Comment

      #3
      Originally posted by oldtimer View Post

      I should mention the bike had a dyno-jet stage 3 installed about 7 years ago. It was 'professionally' tuned at that time. Hasn't run all that well since. Also running pods Bike has 26,560 actual miles and has never been opened.

      Thanks
      To get it right is going to take more TLC than any professional shop is going to do. DIY thing for sure. You didn't mention your elevation, which exhaust you are using, what type of pods, K&Ns or some Emgo "Sand Sifters"?

      Chucks settings are probably a good place to start if you are somewhere near sea level.


      Life is too short to ride an L.

      Comment

        #4
        What main jets did they put in the carburetors, the kit came with two sizes.
        '78 GS1000E, Dyna-S ignition, Dyna Green Coils, K&N pods, Delkevic SS 4-1 exhaust, Dynojet Stage 3 jet kit, Russell SS Brake Lines, Progressive suspension, Compu-Fire series Regulator 55402 and Advmonster cree LED headlight conversion.

        Comment

          #5
          You didn't mention your elevation, which exhaust you are using, what type of pods, K&Ns or some Emgo "Sand Sifters"?
          I believe the elevation here is 720. The exhaust is an unknown 4 into 1. Was a rusty mess when I got the bike. I had them ceramic coated but there is no name. Center stand is retained might be a clue. Pods are el cheapo sand sifters
          Dyno-jet kit still has the 142's in the box, so the 138's are in them.

          Last edited by Guest; 06-30-2015, 05:40 PM.

          Comment

            #6
            Funny, I don't see any pod filters on that bike. Start as Chuck stated and tune from there.

            1980 GS1000GT (Daily rider with a 1983 1100G engine)
            1998 Honda ST1100 (Daily long distance rider)
            1982 GS850GLZ (Daily rider when the weather is crap)

            Darn, with so many daily riders it's hard to decide which one to jump on next.

            JTGS850GL aka Julius

            GS Resource Greetings

            Comment

              #7
              That sure seems to be a stock air box unless it's been modified inside. Looks like they should have put a Stage-1 jet kit in it.
              '78 GS1000E, Dyna-S ignition, Dyna Green Coils, K&N pods, Delkevic SS 4-1 exhaust, Dynojet Stage 3 jet kit, Russell SS Brake Lines, Progressive suspension, Compu-Fire series Regulator 55402 and Advmonster cree LED headlight conversion.

              Comment

                #8
                It' wasan old photo. Probably late 90's. 3 trips of taking the carbs off and on with the stock air box is enough to cure anybody. Stuck on pods and sold the stock system on eBay. Spokes got rusty and I stuck 79 mags on it. Here's a more recent photo. I prefer the spokes but can't find them anywhere. Contacted buchannan but they never responded.

                Last edited by Guest; 07-01-2015, 04:59 PM.

                Comment

                  #9
                  Beautiful bike! Is that a stock paint scheme?
                  Jordan

                  1977 Suzuki GS750 (My first bike)
                  2000 Kawasaki ZRX1100
                  1973 BMW R75/5

                  Comment

                    #10
                    Try the 142 jets with the Pilot fuel screws starting at 1/2 turn out and the air screws 2 turns out. Chucks recommendations are good for a stock setup but a little too far out for the larger jets. If I remember correctly the main jet needle clip position was the third from the top but my memory isn't very good these days. I saw the paper I had the setting on just the other day but can't find it at the moment. I'll find it or call Dynatech tomorrow and post it. My Pilots fuel screws were a little lean so I had to tweak them out about another 1/8 turn to cure a low speed stumble at about 25MPH through town. I get 44MPG on a regular basis and it is very smooth.
                    Last edited by OldVet66; 07-01-2015, 07:13 PM.
                    '78 GS1000E, Dyna-S ignition, Dyna Green Coils, K&N pods, Delkevic SS 4-1 exhaust, Dynojet Stage 3 jet kit, Russell SS Brake Lines, Progressive suspension, Compu-Fire series Regulator 55402 and Advmonster cree LED headlight conversion.

                    Comment

                      #11
                      I have a set of spoke wheels but some of the spokes are starting to rust. I just ordered a Delkevic SS exhaust to replace my old V&H 4-1. It was in too bad a shape to have coated and am tired of painting it, so the spokes will have to wait. The last time I checked they wanted more than the exhaust for SS spokes and threading the wheels.
                      Last edited by OldVet66; 07-01-2015, 07:30 PM.
                      '78 GS1000E, Dyna-S ignition, Dyna Green Coils, K&N pods, Delkevic SS 4-1 exhaust, Dynojet Stage 3 jet kit, Russell SS Brake Lines, Progressive suspension, Compu-Fire series Regulator 55402 and Advmonster cree LED headlight conversion.

                      Comment

                        #12
                        Beautiful bike! Is that a stock paint scheme?
                        Thanks. the paint scheme is my own. After going over a million colors in my mind, I decided to just go with my old high school colors. The maroon and white is paint. the black accent stripes is tape. It was model airplane tape that was supposed to turn to paint in the sun shine. Well it never turned to paint, but it also has never has lofted or come off in 20 years. The front fender was chrome I had ir chemically stripped and painted it to match. I'm not real hip on a lot of chrome and go out of my way to get rid of all I can.. If I wanted to shine it all day, I'd buy an HD

                        Comment

                        Previous template Next
                        Working...
                        X