Announcement

Collapse
No announcement yet.

Vance 4-1 GS850 Exhaust Jetting Question

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Vance 4-1 GS850 Exhaust Jetting Question

    1981 GS850, stock-sealed air box, new oem filter, Vance & Hines Street 4-into-1 Megaphone Exhaust System I just bought

    http://www.bikebandit.com/vance-hines-street-4-into-1-megaphone-exhaust-system?b=287624

    What jets should I run? Mains, pilots, shimmed yes or no? I tried to contact Vance and they said the information is not available for this model.

    Any information would be greatly appreciated.

    Thanks,
    Jon

    #2
    Stage 1 Dynojet kit- for the needle
    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

    Comment


      #3
      what jets should i go to? All I find are stage 3 kits. Where can I get a stage 1?

      Comment


        #4
        Mr. Big is trying to give you the easiest way to get your bike to run perfectly. The Dynojet needle is what you really pay for. It is an adjustable needle with a nice taper to let more fuel flow which is what you need with a free flowing pipe.
        Our Dynojet jet kits for carburetor vehicles is the perfect option for upgrading your air/fuel ratio for more power and speed than ever before. Buy now!

        They do not sell them as cheap as some other places so you may want to shop around.
        You can also go a few sizes on the main jet and shim your jet needle. Shimming the needle is removing the pastic spacer on top of the needle and replacing it with less heigth of washers. You can find the washers at Radio Shack.
        On the the main if you run a stock 115 I'd install a 122.5 or 120. They go in 2.5 increments. Check Denniskirk.com for jets.
        1983 GS 1100E w/ 1230 kit, .340 lift Web Cams, Ape heavy duty valve springs, 83 1100 head with 1.5mm oversized SS intake valves, 1150 crank, Vance and Hines 1150 SuperHub, Star Racing high volume oil pump gears, 36mm carebs Dynojet stage 3 jet kit, Posplayr's SSPB, Progressive rear shocks and fork springs, Dyna 2000, Dynatek green coils and Vance & Hines 4-1 exhaust.
        1985 GS1150ES stock with 85 Red E bodywork.

        Comment


          #5
          cc 850, suz 80-83 all gs850 8 valve, stage 3, part#3306, price 125.89. They only have stage 3, will this have the correct taper needle? I already have a whole slew of jets. The jets included in this set are 155, 160 and 165 mains which are way too big.

          Comment


            #6
            As I said the money you pay for is for the needle. You can by mikuni jets the size you need, The stage three kit is for pods and aftermarket pipe.
            1983 GS 1100E w/ 1230 kit, .340 lift Web Cams, Ape heavy duty valve springs, 83 1100 head with 1.5mm oversized SS intake valves, 1150 crank, Vance and Hines 1150 SuperHub, Star Racing high volume oil pump gears, 36mm carebs Dynojet stage 3 jet kit, Posplayr's SSPB, Progressive rear shocks and fork springs, Dyna 2000, Dynatek green coils and Vance & Hines 4-1 exhaust.
            1985 GS1150ES stock with 85 Red E bodywork.

            Comment


              #7
              With the stock airbox and stock air filter, you may not need to re-jet much at all.

              Read this article: http://www.factorypro.com/tech/carbt...m_engines.html and try it. You won't damage your engine by short runs and you'll know pretty quickly if it's got good power or not.

              You can try shimming your stock needle using the little washers from Radio Shack. You could buy your own parts to go up a main jet or two, but at that point you might as well buy the jet kit.

              Also, the K&N filter for the stock airbox is pretty cheap ($35 from Amazon).
              Last edited by Guest; 04-04-2012, 08:02 AM.

              Comment


                #8
                Look at the '81 850 in my sig (#2 son's bike).
                It has a pipe that I am told might be a Jardine.
                Not real loud, so might not be considered "free-flowing".
                We have 120 mains and stock needles in there and it runs quite well.

                .
                Last edited by Steve; 04-04-2012, 09:50 AM.
                sigpic
                mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
                hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
                #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
                #2 son: 1980 GS1000G
                Family Portrait
                Siblings and Spouses
                Mom's first ride
                Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
                (Click on my username in the upper-left corner for e-mail info.)

                Comment

                Working...
                X