TOPIC:

I ordered a set of Mikuni BS34 carbs from George for my recently aquired 79 KZ1000 LTD. I prefer airbox to pods. Has anyone figured a way to keep and use the factory airbox with these carbs? Are there connector boots from a different bike that would fit these 34mm carbs that I could adapt to the airbox? Maybe Dremel the airbox holes larger to fit those boots then use a K&N airbox filter?

I don't know much about these bikes yet. Could you use another airbox from a bike with a larger engine (and larger carbs)? Maybe someone else can chime in. I am only good for ideas.

Edit: You already have a big engine. hah.

Post edited by: JjSwee, at: 2006/09/11 20:54

83-85 GPz750 has BS34 carbs, perhaps the boots from one of those would work?

My '82 750M1 also has BS34 carbs

Most airboxes have removable rubber intake runners for connecting the carbs. Call Z1Enterprises.com and talk to Jeff. They carry runners for the J motor bikes and perhaps the size that fits into the airbox will be about the size that fits into your airbox. I can't say as I haven't done this. I will eventually figure out a way to adapt an OEM airbox for carb testing the 34s with my KZ900s. I have been toying with using a Z1 airbox and making some adapter fittings to go between the carb flange and the Z1 airbox. I use those for my carb testing as they are easy to pull in and out and easy to clamp onto the carbs. I have some KZ1000 airboxes and these are much more complicated and would be cumbersome to use as I swap carbs out too frequently to spend the time fooling with these.

del

Anyone have an old boot from a BS34 I could have? I don't care if it is hard or has cracks, I just need to use it for test fitting. If I can make this work I'll document it and post it up. I had a lot of experience in a textile manufacturing plant with fans and ducts and my experience says absolutely stay away from the flexable style pipe unless it is very smooth inside!

George, what is the ID on the 900 airbox outlets?

del

Thanks JMK, I'll look into that. On cars I've built we went to great lengths to get carbs and manifolds perferctly matched and straight air passages. I look a my bike and it has offset boots, no velocity stacks, etc. Looks like a couple three horsepower could be gained with some carefull work on the intake arrangement.

The ID on the Z1 airboxes is 43mm I think. The ID you must have is about 52mm. Don't hesitate to think out of the box for a solution. Some of the stuff mentioned... likely plumbing store stuff is good to think about. All you need to do is marry up your existing box with the carbs so most any hose will work as long as you can fasten the hose secure to the airbox. Perhaps you could build a hard tube with a flange on the end using PVC and insert the tube from the inside of the box so that the flange would catch the edge of the hole. The OD of the tube would need to be about OD of the tube would need to be about 52mm. I think it might be possible to cut a flange out of PVC using some existing plumbing fitting and use the PVC solvent to "glue" it to the tube. The flange could be epoxied to the airbox. Once you had that hard tube in place, any tubing that is a bit flexible could be used to join the carbs.

Yes George, inserting the connector from inside the box was along my thoughts too, sounds almost like a velocity stack. That also makes it possible to slide the connectors rearward to remove the carbs. Could use a ring of airfilter foam as the seal under the flange.
Thanks for the measurements and ideas.
Will Piatt

I was wondering if anyone had success with this.

I Just scored a set of BS34's and would like to swap them, removing my VM26 pumpers.

My bike is a 79 KZ1000 LTD (MkII engine) and I am running PMC ZE Cross 4-2 pipes. I would really like to keep my airbox and connect it to the carbs.

Don't mind buying a new set of hoses just was wondering if anyone had succeeded with stock hoses.

I guess I could also retrofit using PVC and rubber pipes.