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If not jetting, then what?

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    #16
    I'm not sure how a single carb can be mounted crooked as you say. They're all connected via a plate. It can be a bit difficult to "pop" the bank in but it's not that hard to put them in all straight. If they spent much time not inserted all the way, the inside of the manifolds could be damaged/indented. It's best to have someone hold one end of the carbs as you pop the other side in. Wipe a little silicone on the carbs and manifolds. With someone helping to hold the other side, place the bank in while focusing on carb #4. Grab the engine just above the #4 header with your right hand, get close to the carb and shove it in with your left. It will "pop" into place. Repeat to the other side while your help is maintaining pressure on the carb already popped in.
    As for what you said about the jetting, if all you've done is changed the mains to 110 and the remaining jetting circuits are stock, you're running VERY lean, as the carb spitting and unstable idle suggests.
    If you can locate a stage 3 jet kit from Dynojet then you can get the jetting improved at all circuits, though the Emgo pods are a compromise. I also have no idea how well the Sebring exhaust flows compared to a Vance and Hines 4 into 1. If you try to re-jet using the factory jet needles, then it's more difficult to get it right.
    Using Dynojet's jetting experience, the factory #15 pilot jets CAN be used with good results in combination with richer pilot fuel screw adjustments. The jet needle circuit is the most important as you spend the most time riding the bike at 1/5 to 3/4 throttle position. If your jet needle's e-clip is in the factory position (3rd groove from the top)(?), you'll probably need to lower the e-clip to the bottom groove (#5), which is as rich as you can make this jetting circuit. Although the Emgo pods create another variable here, I doubt that lowering the e-clip just 1 position will be enough. Possibly position "4 1/2" could work with the Emgo's but I'm just guessing. A "1/2" position is achieved by using a jetting spacer that Dynojet provides in their kit. You place it directly on top the e-clip to achieve a 1/2 position change. Dynojet uses a specially tapered jet needle that works much better than the factory needle. It allows more fuel at various positions and the transition between each jetting circuit is smoother. In any case, every time you disturb the jet needles, you must first carefully bench synch and then vacuum tool synch the carbs. As for the main jet size, I don't remember what size mains your 850 uses as stock. For a reference, the '79 GS1000, like mine, with the same carbs, uses #95 mains. Dynojet sizes their jets differently the Mikuni. Dynojet provides a "138" and a "142" size main jets in their stage 3 kit. Most owners with basic intake and exhaust mod's, use the 138 mains with good results. Dynojet's 138 main jet is the same size as a 130 Mikuni main jet. So in the case of the GS1000 and using Mikuni jet sizing, Dynojet increases the main from #95 to 130, which is 7 full sizes larger. You might try a similar increase depending on what size your mains are. Keep in mind you may have to adjust for the Emgo's. Maybe 1 full size LESS? Then adjust for the Sebring?? IDK.
    To complete Dynojet's jetting requirements, REMOVE the two float bowl vent lines so the bowls can breathe easier and avoid fuel starvation symptoms, especially during windier days/crosswinds.
    But first be sure your manifolds are in good condition and the o-rings replaced.
    And on the seventh day,after resting from all that he had done,God went for a ride on his GS!
    Upon seeing that it was good, he went out again on his ZX14! But just a little bit faster!

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      #17
      Originally posted by DKGS850 View Post

      @LAB3: I have been unable to find non aerosol carb cleaner in Denmark, but in a Danish forum, a 50/50 mixture of "rubbing alcohol" and benzine, have been suggested as an alternative. Which solvents have you been using for your over night soaks?

      BR Michael
      When I got my GS450 I soaked them a few hours in Pine Sol, a common household degreaser here in the U.S. That still didn't do the job and they ended up being dipped a couple of days which did the trick. This method will darken the metal bodies if that's an issue for you but they can be cleaned up.

      I've moved on to an old Goldwing recently and tried Berrymans Carb Dip last week. After a 12 hour soak the parts came out very clean, hard to say if they where cleaner than the Pine Sol dip.

      You'd mentioned having a carb that wasn't sitting the way it was intended, I'd put the effort into getting that taken care of first!
      1980 Yamaha XS1100G (Current bike)
      1982 GS450txz (former bike)
      LONG list of previous bikes not listed here.

      These aren't my words, I just arrange them

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        #18
        The ultrasonic clean is a good alternative to chemical dipping
        Just keep repeating until until the solution remains clear
        And, change the position of the carb body each time. The first couple of runs (8-12 mins/each) I have the airbox side down, as this works on the air jets and idle passages, which tend to be the most clogged. Then, turn the carb 180 degrees and do some more runs. Finally, on the float bowl side
        All the jets. needles, floats, etc can be run a few times. They are rarely the problem, but getting everything nice and shiny is a plus
        Re assemble with new O rings, set the floats and you should be good to go. Be sure to check the numbers on all jets, needles and emulsion tubes/needle jets.
        1978 GS 1000 (since new)
        1979 GS 1000 (The Fridge, superbike replica project)
        1978 GS 1000 (parts)
        1981 GS 850 (anyone want a project?)
        1981 GPZ 550 (backroad screamer)
        1970 450 Mk IIID (THUMP!)
        2007 DRz 400S
        1999 ATK 490ES
        1994 DR 350SES

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          #19
          Originally posted by LAB3 View Post
          When I got my GS450 I soaked them a few hours in Pine Sol, a common household degreaser here in the U.S. That still didn't do the job and they ended up being dipped a couple of days which did the trick. This method will darken the metal bodies if that's an issue for you but they can be cleaned up.

          I've moved on to an old Goldwing recently and tried Berrymans Carb Dip last week. After a 12 hour soak the parts came out very clean, hard to say if they where cleaner than the Pine Sol dip.

          You'd mentioned having a carb that wasn't sitting the way it was intended, I'd put the effort into getting that taken care of first!
          The one solvent that made the old carb cleaners better, and one that not everyone can get their hands on is Methyl Ethyl Ketone (MEK). Fibreglassers know this stuff. MEK also makes a great paint/powder coat stripper. You don't even need that much in your dip, probably 2-5% by volume. Be prepared, it is not a pleasant smelling chemical.
          '83 GS650G
          '83 GS550es (didn't like the colours in the 80's, but they've grown on me)

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