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Mikuni RS36 for the GS1000G

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    Mikuni RS36 for the GS1000G

    I see some posts claim it is too much carb for this bike, what exactly does that mean?

    I don't really want to modify my engine, apart from making it less leaky, I want the oil to remain mainly inside the bike. But I wouldn't mind it being a little faster.

    The advantages:
    1. Less weight
    2. No air box or filter
    3. Easier to remove and put back in
    4. More torque
    5. Faster?


    Disadvantages:
    1. Pods looks stupid
    2. Hard to wash the bike
    3. More fuel usage


    It seems a bit nice to not have the air box.

    Do I need to use the choke with that carb? Not having to deal with that would be great.

    And I have to replace the throttle? Anything else?
    GS1000G 1981

    #2
    Originally posted by Noreg View Post
    I see some posts claim it is too much carb for this bike, what exactly does that mean?

    If the carburetor is "too big" then the engine will not be able to keep enough air flow through the barrels for fuel delivery to occur. It'll bog and have poor throttle response.

    I have a set of RS34s on my bored out 1980 GS1000. I don't think I'd want to go any bigger on carb size. Throttle response is *much* better than with the stock CV carbs with a noticeable power increase.

    Originally posted by Noreg View Post

    Do I need to use the choke with that carb? Not having to deal with that would be great.
    The RS series has a manual choke lever on the side of the carb. I use my only for about 30 seconds when starting from cold and then turn it off.

    Originally posted by Noreg View Post

    And I have to replace the throttle? Anything else?
    You'll need a push/pull throttle cable setup when using RS carbs. I made mine from a GSXR kill switch.

    Bikes:

    1980 GS1000 restomod
    2006 GSXR 750

    Comment


      #3
      You can get a motion pro complete throttle assembly minus the grip for about 60 usd. The rs series carbs are more advanced than what came with your bike so I would not assume a drop in fuel economy. I am presently getting about 42 mpg with my 1100e with rs36, ape pods and free flowing header which is slightly better than when I had stock air box, jetted stock carbs and Vance and Hines exhaust. I have only had these carbs on my bike for just over a year and only wish I put them on sooner.
      1983 gs1100ed restro-mod. 1998 gsxr 1100 almost mint, 2019 kawasaki klx250, 2011 Beta 250 evo trials bike, 2017 Montesa 300rr trials bike, 2021 honda crf250rx woods weapon

      Comment


        #4
        Originally posted by chris View Post
        You can get a motion pro complete throttle assembly minus the grip for about 60 usd. The rs series carbs are more advanced than what came with your bike so I would not assume a drop in fuel economy. I am presently getting about 42 mpg with my 1100e with rs36, ape pods and free flowing header which is slightly better than when I had stock air box, jetted stock carbs and Vance and Hines exhaust. I have only had these carbs on my bike for just over a year and only wish I put them on sooner.
        What would you say is the most important reason for you liking them?

        I get around 47 mpg, but my engine is smaller, and it depends how I ride, I have done better, I have done worse.
        GS1000G 1981

        Comment


          #5
          RS34's are as big as I'd go on a stock size 1000. 32's would probably be better - even more responsive as gas speed would be higher.
          32's will flow more air than the stock carbs anyway.

          Comment


            #6
            Originally posted by GregT View Post
            RS34's are as big as I'd go on a stock size 1000. 32's would probably be better - even more responsive as gas speed would be higher.
            32's will flow more air than the stock carbs anyway.
            The reason I looked at the 36 is that on ebay it said that is what fits my bike.

            Do I need new intake boots for a 32 or 34?
            GS1000G 1981

            Comment


              #7
              Originally posted by Noreg View Post
              The reason I looked at the 36 is that on ebay it said that is what fits my bike.

              Do I need new intake boots for a 32 or 34?
              The RS34s will bolt up into your 81 GS1000G stock intake boots since that bike (and mine) use the 34 mm CV carbs stock.

              Bikes:

              1980 GS1000 restomod
              2006 GSXR 750

              Comment


                #8
                Originally posted by Noreg View Post
                What would you say is the most important reason for you liking them?

                I get around 47 mpg, but my engine is smaller, and it depends how I ride, I have done better, I have done worse.
                I don't have a #1 reason for liking them but I can give you several. They were designed to run with velocity stacks so no problem to run pods and you can get oem parts for them . More than 10 years ago a suzuki dealer told me that there are many parts not available for BS34's, don't know if that is true. I have owned my 1100e since 1986 and it is running the best it ever has, which is really awesome. The engine has never been opened up. I do think the cost of the rs would be hard to justify if you had a working set of stock carbs and wanted to keep your airbox. I have been told that you can't run pods in the rain. I drive when it's raining but was caught in a rain storm for about 40 minutes and nothing bad happened. I am pretty sure the smallest rs carbs are 34mm which is a reason that I would not restore a inline 4 smaller than 750cc. The guy at APE told me that 36's would be best for my stock 1100 4v. I think 34's would be good for a stock 2v. For a few years a 79 1000e was my main source of transportation and I never got close to 47mpg, you must be a very smooth rider.
                Last edited by chris; 09-02-2020, 12:14 AM.
                1983 gs1100ed restro-mod. 1998 gsxr 1100 almost mint, 2019 kawasaki klx250, 2011 Beta 250 evo trials bike, 2017 Montesa 300rr trials bike, 2021 honda crf250rx woods weapon

                Comment


                  #9
                  There is a smaller Mikuni flatslide option around. The immediate predecessor to the RS series were the OE carbs on the first GSXR750 - outside the US. They're 29mm offset bore on the entry and 33mm on the engine side of the slides. There are two needle options available, export and Jap home market. Effectively rich or lean just off idle.
                  They can be bored to 31 or 33mm on the entry side. The racekit for the first GSXR750 had them as 33's. They take the same jets as the RS series. They have accelerator pumps too.

                  A couple of members here have them on GS1000's. I've used them as sets of four - and cut into twins and a single.

                  Comment


                    #10
                    I have see on a forum somewhere that someone sells and or rebuilds the stock carbs for my '92 GSX 1100 G.
                    #3 has a rich condition just off the pilot jets & it bothers me around town.
                    It's to the point that I can only rate my 100% restore a 85% for this issue alone. Carbs have been 'sonic dipped' 2 times now.
                    The bike is now almost a 'showroom' survivor. I plan to sell it when I get this issue worked out. I'm too old & hi mileage to physically handle a 600 lb. bike around town these days.
                    Suggestions / comments?
                    Thanks!
                    Last edited by Mulewright; 09-13-2020, 12:38 PM. Reason: brain fade...
                    Stretching the limits of performance & good taste....

                    Comment


                      #11
                      Quick generic answer:
                      The carb jets require a drop in air pressure at the venturi.
                      When you increase the size of the venturi, you decrease that drop in air pressure AND decrease the velocity of the air at the venturi.
                      Same amount of air through a bigger hole will do that....

                      A stock GS1000 motor doesn't have enough throttle plate vacuum to pull 36mm carbs.
                      I run VM33s on a built Gs1000 (1085 kit, big cams, big valves, Hindle pipe) and the thing WILL NOT carburate correctly at less than 4500rpm. I keep meaning to install 31mm reducers, like Papa Yosh did.

                      You can install 36mm carbs and make it run, but it will never run right.
                      If you're looking for aesthetics look at CRs.

                      Comment


                        #12
                        Just changing to pod filters from the original airbox will cause running issues... you may not enjoy putting large miles on your bike anymore.

                        As for size, I'm running 34s on my 1260...
                        2005 Suzuki Hayabusa
                        2010 Suzuki GSX1250FA
                        2015 BMW RnineT


                        Dave

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