kz 750 carb....im new at this

i just bought a kz 750 and it had the original air filter. so i bought some k&n filters to put on it. when i did this, now i have too much air and not enough gas. is their an adjustment that i can do or do i need to jett the carbs. if so, has anybody done it with the k&n filters and what size do i need?

please help

aaron

what year KZ ?

stock exhaust?

Is it a 750 twin or 4? From all my experience with airbox to pods you have to rejet to allow more fuel. Of course, I've only ever worked on the mikuni vm24 carbs on the kz650s. Not sure about CV type carbs, but I would imagine that they'd need rejetted the same.
For my 650 with pods and a slightly more free flowing exhaust I'm running the stock 15 pilot jets and have upped my mains to 115s (although I'm thinking that 112.5s would be a better match). But still, the mains are several sizes over stock jetting.

If its an early 80s E model 4 cylinder with Keihin ccarbs check here kzrider.com/component/option,com_joomlab...w/catid,3/id,147894/

You need either a 140 and a 70 jet as per wiredgeorge or a 137 and 62 as I did.

Call Z1 Enterprises for the jets. Dont throw out that original airbox just yet....just in case you have problems finding the smaller jet.

Post edited by: JR, at: 2007/07/22 20:44

it is a 1978 kz 750b twin and it has the stock exhaust

anarki650 wrote:

Is it a 750 twin or 4? From all my experience with airbox to pods you have to rejet to allow more fuel. Of course, I've only ever worked on the mikuni vm24 carbs on the kz650s. Not sure about CV type carbs, but I would imagine that they'd need rejetted the same.
For my 650 with pods and a slightly more free flowing exhaust I'm running the stock 15 pilot jets and have upped my mains to 115s (although I'm thinking that 112.5s would be a better match). But still, the mains are several sizes over stock jetting.

I have a 650-4 with pods and freeeee flow exhaust, meaning no insulation just a metal baffle at the end for coppers:evil: . I have 15 pilots 110 mains. I'm thinking of takeing wiredgeorge advise and throughing the 17.5 back in due to I never adjusted the air bleed with the 17.5 so it ran rich at idle, but man did it respond hot and cold, and cold staart was a breeze.it ran good just smoked a lot. So I put back in the 15 pilots.

sorry didnt mean to:)

I dont know about the twins

The problem with sticking pods on the 750 is that the big BS series carbs contain little tiny main jets that are screwed into the float bowls. Since you can't buy these jets (I can't even identify them), rejetting isn't all that easy. There may be ways around the rejetting problem... but using stock type jets (no sizes of these are available to best of my knowledge) with the stock bowls isn't something easily overcome. Hold onto your stock airbox IMHO...

higechops wrote:

it is a 1978 kz 750b twin and it has the stock exhaust

HI higechops, I don't have the B but you might want to check out this link. www.armbell.com/kz400/viewtopic.php?t=43...start=0&mforum=kz400

Also this one,
www.armbell.com/kz400/viewtopic.php?t=363&mforum=kz400
they might give you a starting place.

Good luck
Ron

Post edited by: ronjones, at: 2007/07/24 16:27

wiredgeorge wrote:

The problem with sticking pods on the 750 is that the big BS series carbs contain little tiny main jets that are screwed into the float bowls.

Sorry to get off topic, but ...
George,
How common is it that the Jets get stuck in the bowls?

On my carbs, someone must have buggered the top of the jet with an improper screwdriver size or something...

But I figure, I'll keep the airbox, the jets will never have to come out..

Also, where can I buy new floats for BS carbs?
my brass floats are leaking like the titanic..
:dry:

It is VERY common for the small little jets to have the head stripped. They are puny... I believe I have figured out a way to rejet the BS carbs but will have to work with a 750 owner at some point to confirm how well this works... as far as the floats, I know of no source. That is why we keep "parts carbs"... many of the twin carbs we have purchased via eBay have turned out to be junk and I use parts such as the floats, off of those parts carbs. The brass floats can be soldered if you use resin core solder and a light touch making sure you don't use too much solder to throw off the weight. I guess the ability to solder would also depend on the extent of the damage.

Thanks WG