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    #1

    Jet Needle Question URGENT

    I'm working the carbs on my work bench from my `78 GS1000.

    I've had the jetting done at a shop but I have doubts they adjusted the needle jets in the slides. (They increased the mains from 95 to 102.5)

    Can anyone tell me what the FACTORY LOCATION was for the "C" clip on the needle?
    Theres 5 grooves and right now its in the middle one.

    Hate to sound like "I WANT AN ANSWER NOW DARN IT!!" but I want to get it buttoned up today.

    I guess I'm just trying to set a base as to whether or not they were touched. If the needles have been adjusted then I can back them off 1 notch.....if they HAVEN'T been done then I need to figure out why its running rich elsewhere in the system.

    And since they're out of the bike now, I could get the first adjustment out of the way then go from there.
    Last edited by Guest; 04-02-2010, 05:33 PM. Reason: title change
    Tags: None
    #2
    Third clip
    sigpic

    82 GS850
    78 GS1000
    04 HD Fatboy

    ...............................____
    .................________-|___\____
    ..;.;;.:;:;.,;.|__(O)___|____/_(O)|

    Comment

      #3
      Originally posted by Rick65Cat View Post
      I'm working the carbs on my work bench from my `78 GS1000.

      I've had the jetting done at a shop but I have doubts they adjusted the needle jets in the slides. (They increased the mains from 95 to 102.5)
      Can anyone tell me what the FACTORY LOCATION was for the "C" clip on the needle? Theres 5 grooves and right now its in the middle one.
      Bumping the mains by 3 to 4 sizes works if you have a 4 into 1 installed. #3 is the factory setting. It should not be running rich if the bike is stock except for the 4 into 1. Next determine whether you have the stock needles installed (5DL-36's). Maybe the PO replaced them? The other day you asked about the pilot & air jet setting, have you set those. Did you replace the O-rings?

      Basscliff's website has the GS1000 service manual which has all this & more information
      Last edited by srsupertrap; 03-21-2010, 02:26 PM.
      1979 GS1000E (44 Yrs), 1981 GPz550
      Departed: 1970 Yamaha R5A, 1971 R5B, 1975 Honda XL250, 1983 Suzuki PE175, 1983 CB1100F, 1983 BMW R100RS, 1992 ST1100

      Comment

        #4
        K....

        I know zilch if internal engine mods have been done.

        -There is a Mac 4 into 1 on the bike with the fibre packing(?) still on the baffle. (Its fairly quiet)

        -The stock airbox and lid are still on the bike as is the stock paper filter.

        -And yes, I have replaced ALL the O-rings except for the choke plungers and the fuel cross feed tubes.

        -I screwed the pilot and side air screws back in exactly where they were when I took it apart.
        pilot was 1 1/4 out and the side air screw was 1 1/2 out.

        -Yes the needles are stamped 5DL36.

        An example...the service manual says "pilot air jet - 1.2" Whats the 1.2 mean?... mm?... turns out?

        Thanks for the patience guys.
        Last edited by Guest; 03-21-2010, 02:58 PM.

        Comment

          #5
          The 1.2 pilot air jet is just the size and has nothing to do with turns out. Okay it sounds like everything is stock VM26 carbs. Since you replaced the intake boot, pilot jet and side air screws o-rings I would next check the float level height in all four carbs. IIRC it's set to .95" but check the service manual. Then do a bench synch on the slides, use a gage pin or small screwdriver inserted in the throttle bore in the exact same position to get your slides (4X) in a ball park adjustment.

          I would recommend turning both pilot jet & side air screw out one full turn so it running just a little lean. That way you can turn the screws out to achieve the high idle. BTW what is the size of the pilot jet, it should be a 15; a 17.5 could be causing grief on a stock motor. Install new B8ES plugs start her up and report back.

          Forget to mention the importance of a carb synch @ 3000 rpm once you have all the screws adjusted correctly
          1979 GS1000E (44 Yrs), 1981 GPz550
          Departed: 1970 Yamaha R5A, 1971 R5B, 1975 Honda XL250, 1983 Suzuki PE175, 1983 CB1100F, 1983 BMW R100RS, 1992 ST1100

          Comment

            #6
            Originally posted by Rick65Cat View Post
            K....

            I know zilch if internal engine mods have been done.

            -There is a Mac 4 into 1 on the bike with the fibre packing(?) still on the baffle. (Its fairly quiet)

            -The stock airbox and lid are still on the bike as is the stock paper filter.

            -And yes, I have replaced ALL the O-rings except for the choke plungers and the fuel cross feed tubes.

            -I screwed the pilot and side air screws back in exactly where they were when I took it apart.
            pilot was 1 1/4 out and the side air screw was 1 1/2 out.

            -Yes the needles are stamped 5DL36.

            An example...the service manual says "pilot air jet - 1.2" Whats the 1.2 mean?... mm?... turns out?

            Thanks for the patience guys.

            Cross tubes may not have orings. Wrap em with teflon tape to tighten em up.
            sigpic

            82 GS850
            78 GS1000
            04 HD Fatboy

            ...............................____
            .................________-|___\____
            ..;.;;.:;:;.,;.|__(O)___|____/_(O)|

            Comment

              #7
              Originally posted by srsupertrap View Post
              The 1.2 pilot air jet is just the size and has nothing to do with turns out. Okay it sounds like everything is stock VM26 carbs. Since you replaced the intake boot, pilot jet and side air screws o-rings I would next check the float level height in all four carbs. IIRC it's set to .95" but check the service manual. Then do a bench synch on the slides, use a gage pin or small screwdriver inserted in the throttle bore in the exact same position to get your slides (4X) in a ball park adjustment.

              I would recommend turning both pilot jet & side air screw out one full turn so it running just a little lean. That way you can turn the screws out to achieve the high idle. BTW what is the size of the pilot jet, it should be a 15; a 17.5 could be causing grief on a stock motor. Install new B8ES plugs start her up and report back.
              Float height is bang on at 24mm, (did both sides of each float) spec calls for 23 to 25mm.

              All slides were exactly the same height.

              As for the pilot jet...you mean the one on the bottom of the bowl thats adjustable when the bowl is on? If so, how can you tell the size? Theres no stamping on it.

              4 brand new B8ES's on the work bench waiting to go in.

              Comment

                #8
                Originally posted by Rick65Cat View Post
                As for the pilot jet...you mean the one on the bottom of the bowl thats adjustable when the bowl is on? If so, how can you tell the size? Theres no stamping on it.
                No the pilot jet which resides in the float bowl. It's directly adjacent to the main jet. Check this out Page 3, this will show the VM carb parts and the difference between the pilot fuel screw (outside) and the pilot jet (inside the bowl). This things sound stock but we are just verifying or like nessism likes to say to measure is to know. . . .

                404 Not Found
                http://www.thegsresources.com/files/vm_carb_rebuild.pdf
                1979 GS1000E (44 Yrs), 1981 GPz550
                Departed: 1970 Yamaha R5A, 1971 R5B, 1975 Honda XL250, 1983 Suzuki PE175, 1983 CB1100F, 1983 BMW R100RS, 1992 ST1100

                Comment

                  #9
                  Originally posted by srsupertrap View Post
                  No the pilot jet which resides in the float bowl. It's directly adjacent to the main jet. Check this out Page 3, this will show the VM carb parts and the difference between the pilot fuel screw (outside) and the pilot jet (inside the bowl). This things sound stock but we are just verifying or like nessism likes to say to measure is to know. . . .

                  http://www.thegsresources.com/files/vm_carb_rebuild.pdf
                  Ohhhh....you mean the "bleeder" AKA pilot jet....gotcha.

                  (returns 5 min later)

                  The new ones from my rebuild kits are #15's and the old ones I pulled out are also 15's.

                  Well....I'm just going to put the carbs back in as they are with the new kits and O-rings in them and see how the plugs look. I'll leave the clips on the needles where they are on the #3 groove.
                  Go do plug chops and see.
                  If anything, I'll lower the needles one notch to lean it out.

                  The only jetting change done I can see was the mains. They are now 3 sizes bigger than stock. But that should only come into play under WFO throttle.
                  When I first start it and warm it up, I'll adjust the side screws for idle then take it for a spin.
                  Maybe the internal passages were just dirty. I don't know.
                  I dunked the whole carb assembly in fuel cleaner for a couple of days then blew out all the passages with compressed air.
                  I'll let you know how it turned out.

                  Thanks SRST for the help.
                  Last edited by Guest; 03-21-2010, 05:07 PM.

                  Comment

                    #10
                    Well you probably will have to juggle the various screw adjustments since the carbs are not synched. See if it starts with the choke and idles . . probably won't right away. You might want open up the slides a bit with the idle adjustment knob located between #2 & #3 to compensate.

                    You are on the right track and although you want to button it up today it's probably better to sort out everything first. Other things that may cause a sooty plugs are a oil soaked air filter, a clogged baffle, lousey spark to name a few.

                    Report back and let us know how its running . . .

                    PS: Pilot Mixture air screw rule of thumb: If the air screw is located between the carburetor slide and the engine, turning the screw out richens the mixture. If the screw is between the carburetor slide (VM) and the air cleaner turning it in richens it. Joe Minton
                    Last edited by srsupertrap; 03-21-2010, 05:32 PM.
                    1979 GS1000E (44 Yrs), 1981 GPz550
                    Departed: 1970 Yamaha R5A, 1971 R5B, 1975 Honda XL250, 1983 Suzuki PE175, 1983 CB1100F, 1983 BMW R100RS, 1992 ST1100

                    Comment

                      #11
                      Originally posted by srsupertrap View Post
                      Well you probably will have to juggle the various screw adjustments since the carbs are not synched. See if it starts with the choke and idles . . probably won't right away. You might want open up the slides a bit with the idle adjustment knob located between #2 & #3 to compensate.

                      You are on the right track and although you want to button it up today it's probably better to sort out everything first. Other things that may cause a sooty plugs are a oil soaked air filter, a clogged baffle, lousey spark to name a few.

                      Report back and let us know how its running . . .
                      Air filter looks new. Its not even dirty let alone oil soaked.

                      A clogged baffle isn't going to be hard to check. I might try that this afternoon.

                      Lousy spark?..well, aside from pulling a plug and laying it against the head with the lead on it and cranking the motor...I'm DEFINATELY no whiz on electrical. Maybe the coils are weak?

                      Comment

                        #12
                        Originally posted by Rick65Cat View Post
                        Air filter looks new. Its not even dirty let alone oil soaked.

                        A clogged baffle isn't going to be hard to check. I might try that this afternoon.

                        Lousy spark?..well, aside from pulling a plug and laying it against the head with the lead on it and cranking the motor...I'm DEFINATELY no whiz on electrical. Maybe the coils are weak?
                        The air filter is fine, you got the baffle covered and pulling a plug as you stated is the correct method to check for spark. The suzuki coils are normally okay but the spark plug caps can be suspect and are replaceable. Z-1 Enterprises has them but don't jump to any conclusions . . .

                        Check out the PS rule of thumb in #10 but it sounds like you got this down
                        Last edited by srsupertrap; 03-21-2010, 05:47 PM.
                        1979 GS1000E (44 Yrs), 1981 GPz550
                        Departed: 1970 Yamaha R5A, 1971 R5B, 1975 Honda XL250, 1983 Suzuki PE175, 1983 CB1100F, 1983 BMW R100RS, 1992 ST1100

                        Comment

                          #13
                          For some stupid reason, the baffle won't come out. There only seems to be the one small bolt holding the end cone in. Pull the bolt, grab the end pipe with pliers and it won't even budge.
                          Its too friggen cold out to be laying on the driveway dicking with it.

                          Comment

                            #14
                            If the muffler has ever hit the pavement that will make it out of round making removal of the baffle very difficult. Might try attaching a slide hammer to the baffle to remove it?
                            1979 GS1000E (44 Yrs), 1981 GPz550
                            Departed: 1970 Yamaha R5A, 1971 R5B, 1975 Honda XL250, 1983 Suzuki PE175, 1983 CB1100F, 1983 BMW R100RS, 1992 ST1100

                            Comment

                              #15
                              Pipe is virgin...no impacts at all.
                              And I haven't got a slide hammer.

                              Comment

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