1985 ZX600r carb switch on KZ650

Hello KZ Gurus, I hope all is well. I just received my "air correcting JETS" THANKYOU. It was also suggested that I switch from the VM24s to CVK ZX600r Ninja carbs. I have scored a pretty nice set on Ebay. My question is: do I have to switch the throttle control and cables on my KZ650 over to the ZX600r Ninja system. I will rebuild the CVK carbs but I thought I should askĺ to see if there is anything else I need to know. My KZ650 has an ZX600r Ninja transmission. Thankyou for your time and knowledge.  DustyDeck

Hello KZ Gurus, I hope all is well. I just received my "air correcting JETS" THANKYOU. It was also suggested that I switch from the VM24s to CVK ZX600r Ninja carbs. I have scored a pretty nice set on Ebay. My question is: do I have to switch the throttle control and cables on my KZ650 over to the ZX600r Ninja system. I will rebuild the CVK carbs but I thought I should askĺ to see if there is anything else I need to know. My KZ650 has an ZX600r Ninja transmission. Thankyou for your time and knowledge.  DustyDeck

Please try and keep to one thread per topic, guys get frustrated trying to assist you across multiple threads on the same topic. (I have "merged" your two threads on the same topic)

dustydeck wrote:

Hello KZ Gurus, I hope all is well. I just received my "air correcting JETS" THANKYOU. It was also suggested that I switch from the VM24s to CVK ZX600r Ninja carbs. I have scored a pretty nice set on Ebay. My question is: do I have to switch the throttle control and cables on my KZ650 over to the ZX600r Ninja system. I will rebuild the CVK carbs but I thought I should askĺ to see if there is anything else I need to know. My KZ650 has an ZX600r Ninja transmission. Thankyou for your time and knowledge.  DustyDeck





 

Lots of 650/750 owners have done this CVK32 swap, use the search function to find those. One member on here I know that has done this swap is "rstnick" but not sure if he posted about it on here.

The stock throttle cables will work, nothing special is required.

You will need to buy the unique intake manifolds as the carb spacing is different than 650/750 (head spacing is same) if using a air box you need to also buy the intake rubber ducts then modify the air box openings (easy job) These parts are all still available from Kawasaki. You will also need to adjust the jet sizes going from water cooled to air cooled, there is lots of documentation on what to use.

There are documented threads with pictures on this UK web site :  z650.proboards.com/

I did a similar swap on my 750 engine but used CVK34's off a early Ninja 750. Much harder swap where I had to re-space the carbs.

 

Thanks for the info, I have found "Pablo's Z650Spirit Tutorial" and have found it an invaluable source of information too. He used 45/112 with airbox and stock exhaust. I want to keep my 4into1 so some jetting challenges ahead.

dustydeck wrote:

Thanks for the info, I have found "Pablo's Z650Spirit Tutorial" and have found it an invaluable source of information too. He used 45/112 with airbox and stock exhaust. I want to keep my 4into1 so some jetting challenges ahead.
 

I just re-read that thread, and on page 6 there are a few guys running air box with 4 into 1 pipe on those jet sizes, if anything you may need to go up one size on the main. Pablo also changed his exhaust to a header, looks like a Yosh pipe - You could ask him if he had to swap jets.

Thanks, that's encouraging to read. That's great to know.

Why do people do this swap? Are the VM24's that much trouble? 

82KZ305Belt wrote:

Why do people do this swap? Are the VM24's that much trouble? 

No, the VM22/24 SS carbs work fine.

The CVK carbs are a newer design, half the weight, parts are still available, CV carbs tend to run smoother at all RPMs ("no flat spots").
You can smoothly ride from low RPMs to high in a single gear with no hesitation/flat spot.
It does change the characteristics of the throtle feel; no more throtle by wire, more of a delay feeling, but in a smooth consistant way.


 

I do not think the 24s are problemmatic, rather they are 50 year old (almost) tech and the CVKs are more like 20 or so year old tech. Take a look at some of the project bikes displayed here and see newer tech for forks, swing arms, tires, shocks and  breaks etc that are done on these old machines to increase (at least that is the thought) the ride, and aid in overcoming any of the shortcomings of the older tech. 

I can't speak for others in the group but my VM24s are wore out and I have to make an upgrade and because my KZ650 has a 1985 600r Ninja transmission Im taking the advice of many in the group on the idea that Keihin CVK32s will smooth out the bikes power band and solve some jetting issues at the same time. That's my take away so far. Im going to setup another set of VM24s later with " air correcting jets", another bit of advice from the group. Hard to turn back once you start and it's fun.

dustydeck wrote:

I can't speak for others in the group but my VM24s are wore out and I have to make an upgrade and because my KZ650 has a 1985 600r Ninja transmission Im taking the advice of many in the group on the idea that Keihin CVK32s will smooth out the bikes power band and solve some jetting issues at the same time. That's my take away so far. Im going to setup another set of VM24s later with " air correcting jets", another bit of advice from the group. Hard to turn back once you start and it's fun.



 

I was under the impression you were having trouble because you were running pods without air correctors, but then I kinds of lost the sequence of discussion due to multiple threads covering the topic. I was puzzled when you said people had advised you to swap carbs because I hadn't seen that mentioned until you said you had already decided to. But that may have gotten lost in one of the other threads.   

Anyway I was just curious because I have VM24s on my new bike and they are slated to be rebuilt this winter if not sooner. And I will probably get the air correctors because I doubt I will be able to get the air ducts back on once they come off, and mine are unavailable.