Announcement

Collapse
No announcement yet.

Source for carb diaphragms

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

    Source for carb diaphragms

    Seems to me I was under the impression that diaphragms for "Mick Cooney" carbs where unavailable. Has anyone had any experience with this supplier: http://jbmindustries.com/index.html
    1980 Yamaha XS1100G (Current bike)
    1982 GS450txz (former bike)
    LONG list of previous bikes not listed here.

    I identify as a man but according to the label on a box of Stauffers Baked Lasagne I'm actually a family of four

    #2
    I've never used JBM but in all my searching are the only source for replacement BS34 diaphragms. I've heard of other people using them. If you go for it, I'd be curious to know how they work out.
    1980/1981 GS450 - GS500 Cylinder + Piston Swap - "De-L'ed", custom seat, CB350 bits, 18" rear, etc.
    1977 GS550
    1977 GS750 - Cross country trip thread

    Comment


      #3
      Hi LAB3, I'm looking at these as well. Did you get them? If so how'd it work?

      Do you know what they mean by"roll" the diaphragm??

      Thanks,
      DH
      Rides ROADKILL-1981 GS850G, very slowly these days. :dancing:

      Comment


        #4
        Haven't bought them yet, probably have several more weeks before I take the bike off the road for the winter. As to rolling, there's a good many pictures and instructions on that site, anything other than that would be speculation and I would hate to have you rip your new ones by giving an uninformed guess.
        1980 Yamaha XS1100G (Current bike)
        1982 GS450txz (former bike)
        LONG list of previous bikes not listed here.

        I identify as a man but according to the label on a box of Stauffers Baked Lasagne I'm actually a family of four

        Comment


          #5
          Originally posted by LAB3 View Post
          Haven't bought them yet, probably have several more weeks before I take the bike off the road for the winter. As to rolling, there's a good many pictures and instructions on that site, anything other than that would be speculation and I would hate to have you rip your new ones by giving an uninformed guess.
          Thanks LAB3. JBM sent me this:

          "Best way to describe rolling is with pictures...





          It refers to the process of having waves in the diaphragm to make it flat."

          Guess I'm dumb here. Wish the vid said, "This is what JBM means by rolling." But he didn't and the statement about having waves makes me think I should take it down to the ocean and throw them in first. Waves make it flat??? Are they saying to roll the outer edge to make the piece sit flat in the groove in carb body? Are you supposed to roll the diaphragm in your hands to "loosen" it up before assembly?? Just wish there was an actual video/image to clearly show this if so important. Unless I missed something while watching.

          For all their statements about the importance of this, & including the process as not something to miss in the FAQ about what you can do wrong, I'd love to see it just a bit clearer.

          Anyways. I think this item would be a good thing for my GS850 but not sure if that in itself would cure the running issues she has developed. Will attempt to clarify the term "roll" while enjoying a bagel.

          DH






          Rides ROADKILL-1981 GS850G, very slowly these days. :dancing:

          Comment


            #6
            My diaphragms are still in tact as far as I can tell but as with anything that's 36+ yrs old and made of rubber it's just a matter of time before they give out. Having just completed nearly five months on the road and shooting for six or more next year I'm hoping to be able to keep from getting stuck somewhere waiting for a part or having to pay full retail for the same thing I can order somewhere else for half the price.
            1980 Yamaha XS1100G (Current bike)
            1982 GS450txz (former bike)
            LONG list of previous bikes not listed here.

            I identify as a man but according to the label on a box of Stauffers Baked Lasagne I'm actually a family of four

            Comment


              #7
              Rolling the diaphragm seems pretty simple to me. The arrow points to the roll, what the diaphragm should look like when installed, the finger points to the roll. The tire is the thick rubber of the hole for the slide.



              V
              Gustov
              80 GS 1100 LT, 83 1100 G "Scruffy"
              81 GS 1000 G
              79 GS 850 G
              81 GS 850 L
              83 GS 550 ES, 85 GS 550 ES
              80 GS 550 L
              86 450 Rebel, 70CL 70, Yamaha TTR125
              2002 Honda 919
              2004 Ural Gear up

              Comment


                #8
                Originally posted by gustovh View Post
                Rolling the diaphragm seems pretty simple to me. The arrow points to the roll, what the diaphragm should look like when installed, the finger points to the roll. The tire is the thick rubber of the hole for the slide.



                V
                Thanks gustovh. The trouble I was having in understanding was this.

                did "roll" mean the verb and some method of actually rolling the material of the rubber diaphragm to, I don't know,...soften it up or did it mean rolling the outer edge and the "tire" that fits into the groove of the metal slide or some other action involving manipulating actively the rubber. Or, did it mean, as you see it, just seating the diaphragm such that there is a roll as in the picture. Kinda like is roll a verb or a noun?
                Your answer sort of makes a lot more sense so If & When I get these, I promise not to roll them around waiting for some miracle transformation.

                Thanks for you getting back to me on this.

                DH
                Rides ROADKILL-1981 GS850G, very slowly these days. :dancing:

                Comment


                  #9
                  I used them on my old Kawasaki. they were easy to install.
                  I had to cut the old ones off and the plastic retainer.
                  the JBM ones were a lot thicker around the hole, they came with instructions and they worked just fine.
                  Last edited by derwood; 11-04-2018, 12:33 PM.
                  GSX1300R NT650 XV535

                  Comment


                    #10
                    Hi, after a long delay, I installed my first JMB Diaphragm on #1 carb.

                    Easy to cut the upper & lower plastic retainers,....even I could do it.

                    Cleaned up the groove in the top of the slide with carb clean & Nylon parts brush. The outer top edge of the slide was a bit rough so I got a very fine file and with the utmost gentlemanly strokes I lightly took most of the roughness off. This was done with the utmost care so as not to take off any metal save the worst of the "burrs".

                    Noting that the pinhole in the bottom of the slide faces forward toward the engine I put a red dot to mark that position and aligned that dot properly with the carb's orientation. I made note of the "dip" in the upper carb surface where the old diaphragm fit in and used a marking on the top of the new diaphragm as a pointer.

                    The new diaphragm slipped on with minimal effort and can be rotated within the groove to get all aligned as needed. I then put a small drop of red nail polish to show where to set up for future hoodledoodling with slides.

                    The only issue I see is that these are much thicker than the OEM diaphragms and a bit stiff and not lying true as to the "roll". I had mentioned this to JMB in email & was told to lightly warm with a hair dryer & they will cooperate and look as nice as in the pics on the JMB site.

                    Got late had to stop,more to follow.

                    Main point, If an idiot like me can get this far successfully anyone should be able to do it like a pro.

                    I remain,

                    DH
                    Rides ROADKILL-1981 GS850G, very slowly these days. :dancing:

                    Comment


                      #11
                      Sure looks easier than the hoops I jumped through.
                      Wish I had known about about it then.
                      https://www.thegsresources.com/_foru...nt-oh-what-fun!
                      The Three Horsemen
                      '85 GS1150ES (Current Income Eater)
                      '83 GS1100ES
                      ‘77 XLCR

                      "Never ride faster than you can see. Besides, it's all in the reflexes."
                      Porkchop Express

                      Comment


                        #12
                        Originally posted by Greg B View Post
                        Sure looks easier than the hoops I jumped through.
                        Wish I had known about about it then.
                        https://www.thegsresources.com/_foru...nt-oh-what-fun!
                        Hi Greg, WOW! Some project. Don't know when JMB started making these in general & the ones that fit my carbs in particular. Perhaps with your fantastic skill set you could build a "way back machine" or a flux capacitor for your DeLorean and bring a set of the JMB diaphragms back to 2010 to figure the easier way out. But maybe you would decide it was more fun to use your elegant equipment and abilities to go your own way.

                        Very impressed I must say. I would take my hat off to you but every time I do that I put it down somewhere and can't find it.

                        DH
                        Rides ROADKILL-1981 GS850G, very slowly these days. :dancing:

                        Comment

                        Working...
                        X