1979 kz400 Ltd Carb issues

Hello all, new here as I just got my first motorcycle last week a 79 kz400 ltd! It's running not too bad right now. The bike came with pod filters which from reading he forums is a no-no with stock carbs so I am looking into finding an air box for the bike. I'm also looking into changing the carbs on the bike. The stock ones are working now but I'd like the change then to a different style. Either older model carbs or different all together. I've heard pros and cons of going to mikuni vms but not sure I'm there yet and want to deal with the hassle of them. I'm more looking into older model carbs like the cvb36s or something along those lines. Is there any changes that would need to be made to accommodate them? Any insight in carb help would be amazing any info com carb swaps would be even better. Thanks in advance all!

Did you check the jets to see if the previous owner changed them to accommodate the pods? If the bike is running well, that may have already been done for you. If it's not running all that great, it could just be a matter of figuring out what size your jets need to be.

You're smart to be looking for an airbox because that will remove all the mystery. In any case, I wouldn't be in a big hurry to replace the carbs on a running bike just for the heck of it.

-Barry

No I have not I did take the bottoms off and spray carb cleaner through everything but did not check jets. I'll have to find a parts diagram to find where everything is. Thesee carbs are a mystery to me I believe the idle screw is messed up? If I play with the screw in the middle of the carbs I can get it to idlenjust fine but the one one the side where the choke is doesn't do much

Do you have a factory service manual? If not, getting one would make your life a lot easier. The link below covers all the general info on your carbs including a detailed diagram and a table with factory the jet setup.

www.kz400.com/Workshop%20manual%20bilder...nual%20p.150-155.pdf

And this is the site it came from (good stuff there):
www.kz400.com/

One wonderful thing about having pod filters is that they make removing the carbs a pretty simple process. If I were you, I'd pull them and figure out what you have for jets. If the jets match the factory settings, you have some work ahead of you as long as you're running pods. I really can't offer much advice there. Some guys have had success by finding away to block a large portion of the airflow coming from the pods. Maybe you could experiment with that first if you find out you have factory jets.

While the carbs are off, you can also give them a good cleaning and investigate any weirdness with your idle screw.

Best bet is still to get your hands on an airbox. No luck searching ebay?

-Barry

I do have a service manual 2 came with the bike Haynes and clymer? Also 2 oil filters and 2 blank kawasaki keys and a gasket kit for the engine. I will check jets and stuff this weekend when I get a chance and get a better grip on things. I did order a pair of kz 440 carbs to tinker with as well if my carb issue is more than fixable.

I have had no such luck locating a stock airbox for the 400. I found 2 for the 440 that were do able but would need to come up with a filter compartment.

www.kawasakimotorcycle.org/forum/vintage....html#/topics/156774

The link I psated is to someone who created their own air box and had geat work with it. I'm going to give this a shot with an aluminum box instead of a plastic one. Just need to find a good epoxy to bond to aluminum and pvc.

As I search various forums I come across so many things. Ive read kz400.com until my eyes bleed and can't find the exact info I'm looking for. Will kz440 carbs make a difference in my 400? So many questions so little time

-Matt

No eBay APP ID and/or Cert ID defined in Kunena configurationNo eBay APP ID and/or Cert ID defined in Kunena configurationHi Matt,

Most guys around here swear by the Kawasaki manuals but maybe you don't need a 3rd one at this point - especially since you can look it up on kz400.com.

That homemade airbox is pretty awesome. It got me thinking though... Since the 400 LTD airbox is available, but the filter assembly is impossible to find, maybe it would be easier to modify the stock airbox to use the same type of filter that guy used. Am I making any sense?

I'm sure you've already found this, but just as a point of reference:


You could even go this route to solve the filter problem (you know, after you make it look better):


Regarding the 440 carbs, they're probably close enough that you can run them without any trouble but there's only one way to find out...

-Barry

Barry,

Yes I was looking at that exact airbox earlier but wasn't sure what it was missing until later on. I'm sure I could.fab something up to replace the filter compartment that would be too hard I believe.

I really like the custom idea for it as it looks a lot nicer and is about the same price when you add everything up. Just a matter of preference I guess at this point.

That being said if I do go the customost route, do you happen to know what I could use to bond the aluminum to abs plastic or pvc for that matter? I was wondering also what the dimensions were for the carb boot holes so I can find a rubber coupling that will fit for the carbs.

So many questions and can only find so little answers. HA

-Matt

The benefits of starting with a stock airbox are that you get as close as possible to the correct airflow dynamics, should be a lot less work, and the carb boots are a perfect fit.

That said, I agree that the homemade version does look great.

I can't help you with the epoxy but there must be something in the JB Weld product line that would work. If you're building your own, I don't think it's important to exactly match the air holes. You can just use the carb air intake diameter to design your boots (maybe out of a radiator hose?) and make your box to fit them. Again, having the stock air ducts would be a big help there.

If you do this, you definitely have to post some pics.

-Barry

Barry,

I didn't get a chance to make a box yet. I bought one but it just didn't fit in the space it needed to go. I ordered new jets a variety of sizes to start trying to rejet the bike. If I wind up back at square on with these I'm either ordering a box and going to mcguyver up a filter housing, make an airbox with parts provided by v3dt, or pouring kerosene on everything and just lighting a match. HA!

Barry,

I didn't get a chance to make a box yet. I bought one but it just didn't fit in the space it needed to go. I ordered new jets a variety of sizes to start trying to rejet the bike. If I wind up back at square on with these I'm either ordering a box and going to mcguyver up a filter housing, make an airbox with parts provided by v3dt, or pouring kerosene on everything and just lighting a match. HA!