Can i switch these carbs?

hello
i have only been on this website for a couple of days and got tons of great info already. but i need some higher knowledge again. i own a 1981 kz1000 ltd and i want to know if i can use these carbs on it. They came off a 1985 gpz750. Anything anybody can tell me would be appreciated. Will performance change? They both have 34 mm openings.

the carbs i have on my kz1000 right now look like this... does anybody know what the 4 holes are for onthe inside? Or if there will be a difference going to 2 holes?

if i cant use these carbs then i am open to suggestions on which ones i should use to increase power.... thanks

You can use any carbs you want as long as the spacing is correct. Some things might be different such as jets, intake boot size, choke cable placement and throttle cable placement.

They should be usable. They will provide basically the same effect I guess, but put them on, I don't think it will hurt the bike. Check the jetting though!

BarMan wrote:

if i cant use these carbs then i am open to suggestions on which ones i should use to increase power.... thanks

if they are both 34mm i dont see where the hp gain will come from unless your origionals are toast.does your bike have a pipe ,good filters on it?

the ones i have right now have been sitting for a couple of years with gasoline in them... i will probably find time to rebuild them but not right now... the ones from the gpz have a stage 3 jet kit. i am not quite sure what that means since this is my first motorcycle.---- i have kerker header with emgo pod filters

Post edited by: BarMan, at: 2007/05/20 18:16

Post edited by: BarMan, at: 2007/05/20 18:34

ah,now it makes sense!

It seems there are BS34's and BS34's

As you obviously know, the 83-85 GPz750 used BS34 carbs, as did the 81-82 KZ1000J/K/M.

Now, I don't have a KZ1000J/K/M here at the moment, but I do have a new set of KZ1000J/K/M carb holders (intake manifolds), along with a GPz1100 throttlebody set, and GPz750 heads. The throttlebody fits the J/K/M carb holders perfectly, but it won't fit the GPz750 carb holders. And the J/K/M carb holders are ~1/4" larger in diameter than the GPz750 ports.

That indicates to me that the BS34's used on the KZ1000J/K/M are ~1/4" larger in diameter on the head side than the GPZ750 BS34's.

My guess is, if you stick the GPz750 carbs in the carb holders on your 81 KZ1000K, then they are going to fall right back out again

Disclaimer:
I am no carb guru, I intensely dislike carbs, EFI is the greatest thing since sliced bread


neilage66, I will go ahead and delete your post, those fumes must have gotten to you so bad you posted in the wrong thread

Post edited by: steell, at: 2007/05/20 19:07

Hey steell: I tried to edit the photo out and repost but my screen said "hacking attempt"...wow, was that you? :laugh: Haven't seen that before, thanks to goodness. :whistle:

Gas + decade = yicky smelling, e-vile, foul material!

the small holes are for air bleed passages.
the difference is minor and is a different carb body that does the same job.

carb exchange is possible but there are common differences to consider
insulator boot diameter
jetting
head port spacing

The extra holes are for venting the float bowl. Note on the GPz BS34, there is a plastic tee fitting between each of the carb pairs for that purpose. The ID and OD on both sides of the GPz carbs and the BS34s from the KZ1000 model you show are the same. The one thing to check is the shape of the outside of the end that fits in the carb holder. There are two styles of carb holder as the molding of them is different due to the different shape of the outside of part that goes into the carb holder. If you use the wrong carb holder, you must tighten up the clamps to the point where the carb holder will eventually be damaged.