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  • Keihin to Dynojet to Mikuni carb jet conversion chart

    I'd never seen this on Hawkgtforum and it was hard to find online, so I figured I'd post it here in case anybody gets in a pinch and wants to use other jets but doesn't know how they convert.



    Width------Keihin # -- DynoJets # -- Mikuni #

    0,0540---- 140--------- 130--------- 121,9
    0,0550---- 142,5------- 132--------- 123,8
    0,0560---- 145--------- 134--------- 125,6
    0,0570---- 147,5------- 136--------- 127,5
    0,0580---- 150--------- 138--------- 129,4
    0,0590---- 152,5------- 140--------- 131,3
    0,0600---- 155--------- 142--------- 133,1
    0,0610---- 157,5------- 144--------- 135,0
    0,0620---- 160--------- 146--------- 136,9
    0,0630---- 162,5------- 148--------- 138,8
    0,0640---- 165--------- 150--------- 140,6
    0,0650---- 167,5------- 152--------- 142,5
    0,0660---- 170--------- 154--------- 144,4
    0,0670---- 172,5------- 156--------- 146,3
    0,0680---- 175--------- 158--------- 148,1
    0,0690---- 177,5------- 160--------- 150,0
    0,0700---- 180--------- 162--------- 151,9
    0,0710---- 182,5------- 164--------- 153,8
    0,0720---- 185--------- 166--------- 155,6
    0,0730---- 187,5------- 168--------- 157,5
    0,0740---- 190--------- 170--------- 159,4
    0,0750---- 192,5------- 172--------- 161,3
    0,0760---- 195--------- 174--------- 163,1
    0,0770---- 197,5------- 176--------- 165,0
    0,0780---- 200--------- 178--------- 166,9
    0,0790---- 202,5------- 180--------- 168,8
    0,0800---- 205--------- 182--------- 170,6
    0,0810---- 207,5------- 184--------- 172,5
    0,0820---- 210--------- 186--------- 174,4
    0,0830---- 212,5------- 188--------- 176,3
    0,0840---- 215--------- 190--------- 178,1
    0,0850---- 217,5------- 192--------- 180,0
    0,0860---- 220--------- 194--------- 181,9
    '88 Hawk GT - back in the saddle
    '99 Suzuki GZ250 - the first

    '87 Suzuki GSXR1100/1207cc - traded to get my Hawk back

  • #2
    Good stuff, thanks, Isaac!
    '99 Ducati 748 with a 996 conversion

    Comment


    • #3
      I have mikuni small head main jets in my carbs right now, and they threaded easily, for the umpteenth time.
      '88 Hawk GT - back in the saddle
      '99 Suzuki GZ250 - the first

      '87 Suzuki GSXR1100/1207cc - traded to get my Hawk back

      Comment


      • #4
        how big is your hole??

        Now that's something you can't find in a factory shop manual!!
        good info, thanks for posting...
        you found it where?
        "It's only getting worse."


        MY rides: '97 VFR750, '90 Red Hawk, '88 Blue/Black Hawk, '86 RWB VFR700 (3), '86 Yamaha Radian, '90 VTR250, '89 VTR250 (2), '73 CB125, '66 Yamaha YL-1

        Sold: '86 FJ1200, '92 ZX-7, '90 Radian, '73 CB750, '89 all-white Hawk, '88 blue Hawk, '86 FZ600, '86 Yam Fazer 700 , '89 VTR250, '87 VFR700F2, '86 VFR700F.

        Comment


        • #5
          I found that particular list on a Yamaha TRX450 web forum. I was looking for a keihin to mikuni conversion chart because I already knew they fit on my bike and wanted to know how far off the numbers were. Turns out it's a pretty huge jump.
          '88 Hawk GT - back in the saddle
          '99 Suzuki GZ250 - the first

          '87 Suzuki GSXR1100/1207cc - traded to get my Hawk back

          Comment


          • #6
            Every week or so I look for an old thread and add to it

            Width------Keihin # -- DynoJets # -- Mikuni #

            0,0540---- 140--------- 130--------- 121,9
            0,0550---- 142,5------- 132--------- 123,8
            0,0560---- 145--------- 134--------- 125,6
            0,0570---- 147,5------- 136--------- 127,5
            0,0580---- 150--------- 138--------- 129,4
            0,0590---- 152,5------- 140--------- 131,3
            0,0600---- 155--------- 142--------- 133,1
            0,0610---- 157,5------- 144--------- 135,0
            0,0620---- 160--------- 146--------- 136,9
            ..........
            0,0800---- 205--------- 182--------- 170,6
            0,0810---- 207,5------- 184--------- 172,5
            0,0820---- 210--------- 186--------- 174,4
            0,0830---- 212,5------- 188--------- 176,3
            0,0840---- 215--------- 190--------- 178,1
            0,0850---- 217,5------- 192--------- 180,0
            0,0860---- 220--------- 194--------- 181,9

            Keihin "393" series:
            The Keihin sizing is pretty close to right. Close enough for hand drilling a jet when you don't have what you need. A 150 is 1,50mm in diameter.

            Factory Pro "K Series":
            The Factory Pro "K Series" jets are dimensionally sized, just like the Keihin jets.
            Example: a "150" Keihin or "K Series" main jet is usually, 1.50mm in diameter.

            According to dynojet, http://planetminis.com/f21/finally-f...ets-52984.htmlthe dynojets are supposed to be sized the same as Keihin (dimensionally)- but I've never found that to be true.
            As far as different lead-in angels and such, I'm guessing that that difference is more that metric manufactured jets tend to have a std 90 degree included angle and USA manufactured jets tend to be 82 degree included angle. I could be wrong on the lead-in angle - as it was 15 years ago that we started making Keihin style jets.

            Mikuni N102221 (small round slotted jets)
            That part of the chart is just wrong. You have to take a selection of jets, across the range and measure them.

            Summation -
            If you have a pile of a certain brand of jet and you want to use them, it's up to you. I've seen and tuned Keihin carbs jetted with Mikuni jets that "squeak" that last 1/2 turn (the threads are .05mm different) and vice versa. Heck - I've even used dynojet jets if there's not anything else available.

            But - if you are using a particular brand of jet, don't swap brands of jets using this dj and Mikuni cross reference chart

            Thanks -

            Marc Salvisberg
            Factory Pro Tuning

            Comment


            • #7
              And that my friends, is truly what you'd call "straight from the horse's mouth."
              J.D. Hord
              Keeper of Engine Nomenclature, 9th Order

              Comment


              • #8
                conversion chart

                Originally Posted by isaac View Post
                I'd never seen this on Hawkgtforum and it was hard to find online, so I figured I'd post it here in case anybody gets in a pinch and wants to use other jets but doesn't know how they convert.



                Width------Keihin # -- DynoJets # -- Mikuni #

                0,0540---- 140--------- 130--------- 121,9
                0,0550---- 142,5------- 132--------- 123,8
                0,0560---- 145--------- 134--------- 125,6
                0,0570---- 147,5------- 136--------- 127,5
                0,0580---- 150--------- 138--------- 129,4
                0,0590---- 152,5------- 140--------- 131,3
                0,0600---- 155--------- 142--------- 133,1
                0,0610---- 157,5------- 144--------- 135,0
                0,0620---- 160--------- 146--------- 136,9
                0,0630---- 162,5------- 148--------- 138,8
                0,0640---- 165--------- 150--------- 140,6
                0,0650---- 167,5------- 152--------- 142,5
                0,0660---- 170--------- 154--------- 144,4
                0,0670---- 172,5------- 156--------- 146,3
                0,0680---- 175--------- 158--------- 148,1
                0,0690---- 177,5------- 160--------- 150,0
                0,0700---- 180--------- 162--------- 151,9
                0,0710---- 182,5------- 164--------- 153,8
                0,0720---- 185--------- 166--------- 155,6
                0,0730---- 187,5------- 168--------- 157,5
                0,0740---- 190--------- 170--------- 159,4
                0,0750---- 192,5------- 172--------- 161,3
                0,0760---- 195--------- 174--------- 163,1
                0,0770---- 197,5------- 176--------- 165,0
                0,0780---- 200--------- 178--------- 166,9
                0,0790---- 202,5------- 180--------- 168,8
                0,0800---- 205--------- 182--------- 170,6
                0,0810---- 207,5------- 184--------- 172,5
                0,0820---- 210--------- 186--------- 174,4
                0,0830---- 212,5------- 188--------- 176,3
                0,0840---- 215--------- 190--------- 178,1
                0,0850---- 217,5------- 192--------- 180,0
                0,0860---- 220--------- 194--------- 181,9
                This is the stuff!!!
                Emotion is a terrible thing to fight while in the heat of passion...
                Governments Don't Create Jobs..Private Business Does...

                Comment


                • #9
                  Gotcha!

                  Nice find.

                  Comment


                  • #10
                    now..if you make sense out of these two charts, clue me in..I must have gotten some Soma in my coffee recently.
                    Emotion is a terrible thing to fight while in the heat of passion...
                    Governments Don't Create Jobs..Private Business Does...

                    Comment


                    • #11
                      Originally Posted by marc99 View Post
                      Keihin "393" series:
                      The Keihin sizing is pretty close to right. Close enough for hand drilling a jet when you don't have what you need. A 150 is 1,50mm in diameter.

                      Factory Pro "K Series":
                      The Factory Pro "K Series" jets are dimensionally sized, just like the Keihin jets.
                      Example: a "150" Keihin or "K Series" main jet is usually, 1.50mm in diameter.

                      ...

                      Marc Salvisberg
                      Factory Pro Tuning
                      Here it is. Maybe the Mikuni's are flow-rate sized? OR the Dynojets? But if one is flow rate, what's the other?

                      Excellent find at any rate.
                      Last edited by Larkin; 11-18-2010, 04:03 PM.

                      Comment


                      • #12
                        I am with you larkin..as far as I can see it..flow rated..but @ what pressure..ambient sea level..14.9 #/sq in ? it may explain why altitude affects jet size in a given engine..my head is swirlling form Soma or unexpected usage..
                        Emotion is a terrible thing to fight while in the heat of passion...
                        Governments Don't Create Jobs..Private Business Does...

                        Comment


                        • #13
                          Originally Posted by marc99 View Post
                          But - if you are using a particular brand of jet, don't swap brands of jets using this dj and Mikuni cross reference chart
                          Ahhh Here it is... The chart I was looking for.
                          Gino

                          2012 CCS LRRS ULSB Champion
                          2012 CCS LRRS P89 Champion
                          2008 CCS ULSB National Champion
                          LRRS HAWK GT Racer CCS Expert #929
                          ECK RACING


                          Chain Roller

                          NEVER UNDERESTIMATE THE PREDICTABILITY OF STUPIDITY

                          Comment


                          • #14
                            I Didn't even see this... Marc was here... Cool !

                            Dam I missed him ! I would have loved to say hello, back in '87 he tuned my VFR700F2 at his Marin County shop.

                            After that...It ran like f'n jet stink.

                            Great guy Great Tuner !

                            Thanks again Marc !

                            Aloha Bart D.

                            Originally Posted by marc99 View Post
                            Keihin "393" series:
                            The Keihin sizing is pretty close to right. Close enough for hand drilling a jet when you don't have what you need. A 150 is 1,50mm in diameter.

                            Factory Pro "K Series":
                            The Factory Pro "K Series" jets are dimensionally sized, just like the Keihin jets.
                            Example: a "150" Keihin or "K Series" main jet is usually, 1.50mm in diameter.

                            According to dynojet, http://planetminis.com/f21/finally-f...ets-52984.htmlthe dynojets are supposed to be sized the same as Keihin (dimensionally)- but I've never found that to be true.
                            As far as different lead-in angels and such, I'm guessing that that difference is more that metric manufactured jets tend to have a std 90 degree included angle and USA manufactured jets tend to be 82 degree included angle. I could be wrong on the lead-in angle - as it was 15 years ago that we started making Keihin style jets.

                            Mikuni N102221 (small round slotted jets)
                            That part of the chart is just wrong. You have to take a selection of jets, across the range and measure them.

                            Summation -
                            If you have a pile of a certain brand of jet and you want to use them, it's up to you. I've seen and tuned Keihin carbs jetted with Mikuni jets that "squeak" that last 1/2 turn (the threads are .05mm different) and vice versa. Heck - I've even used dynojet jets if there's not anything else available.

                            But - if you are using a particular brand of jet, don't swap brands of jets using this dj and Mikuni cross reference chart

                            Thanks -

                            Marc Salvisberg
                            Factory Pro Tuning
                            "Hawk Porn" http://picasaweb.google.com/11124379...eat=directlink 1990 NT650-Penske 8981, Race-tech Springs & Gold Valves, Steve Lenac six-piston caliper & EBC rotor,SS Brake lines Ft / Rear lines through SSA ,VFR brake lever, F2 front wheel, F-120/70 R-160/60 Dunlop Roadsmart, Full-Supertrapp Exhaust, Stage 1 Jet kit, K&N Filter, Corbin Seat, Pro-Tec Clip-On's/ Past Rides...1986 VFR700F2 Interceptor / 1979 Yamaha Rd400 Daytona Special

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