Help with jetting a 77 kz400 please.

[jchaplin]

Starting my winter project. I'm new here so I'll introduce myself shortly with bike pics of the work so far. Total barn find, 7800 miles, complete. Going down to the frame and making it a beautiful little cafe creation. No airbox, rebuilding stock carbs, want to find scrambler style exhaust. What jets should I look for since I am not using the airbox? Thanks,

 

[jchaplin]

Pics of where I am right now. Getting her running first, then tear down for polish and paint.

 

[teddpage]

I hate to break it to ya, but its probably going to be a lot of trial and error when it comes to jetting. Each bike is different.
You will probably have to go up a size or 2 to begin with, do some plug chops, etc.
Before we go too far, do you have CV type carbs? Or are they slide type? CV carbs usually don't take well to Pod filters without a lot of work, whereas slide types are (usually) easier to tune.

 

[danker16]

I'd honestly try to find an airbox for it, the money, time and effort for mediocre performance you'll get with PODS just don't justify it.
go with the airbox.

 

[xb33bsa]

spend the $40 or so to get a stock airbox,there is plenty of them on ebay

 

[Nebr_Rex]

See if you can locate some new carb boots before you get carried away with
buying jets and pods or air box. You might have to get it running on the stock
carbs and switch to something else. I never messed with the CV carbs on the
400, I just swapped out to the 440s. The early 400 carbs are a pain to work with
in stock configuration let alone modified. Try doing a search at KZRider.com
and KZ400.com for more specific information. The early 400 carbs have a different
spacing then the late 400 and 440 if you didn't already know.

.

 

[jchaplin]

I think they are cv. I want to go with pods if I can for looks and easy of access. I have an airbox for it. I took it off so I could get the carbs out. They were locked up and need rebuilt. If I need to get a different set of carbs, I'd like to know what might be the best alternative since I plan to modify the bike. Thanks.

 

[xb33bsa]

so you are going for looks ...check...don't care about performance....check
would rather spend countless hours with a poor running pos pulling apart your carburetors and pulling out your hair,....than ride ....check ??? ???

 

[jchaplin]

Yeah that's exactly what I said. Every one of these bikes exactly like mine done in cafe style has pod air filters and no airbox so clearly it is possible and there is some configuration that works. I do want it to be functional first but there is no reason it can't look good to.

 

[Nebr_Rex]

See if you can get the stock carbs cleaned up and the bike running.
Also checking the valve lash and ignition as per the manual. As for different
carbs get some Mikuni vm28 or vm30 round slides along with Uni or K&N
filters. Anything bigger will be to much for 400cc.

 

[teddpage]

Can Pods be made to work with CV carbs? Yes. I have them on my bike, but its not ideal. I plan on swapping to slide type carbs like Mikuni VM's when money allows.
It just takes a lot of messing around with Jets and settings to get the bike to run well.

 

[xb33bsa]

even if you get the jetting right you will loose top end horsepower with pods they wont flow enough air

 

[Nebr_Rex]

even if you get the jetting right you will loose top end horsepower with pods they wont flow enough air

Bullshit.

 

[xb33bsa]

Bullshit.

if you think a little tiny pod can flow as much air as the factory engineered airbox, well you are an idiot

 

[Nebr_Rex]

Why don't you go measure the inlet of that air box? Einstein.

 

[xb33bsa]

of course you open the breather holes a bit and or or loose the snorkel , everybody knows that :
but the airbox with it's intake runners and resonance is far superior to any shit pods

 

[Nebr_Rex]

Like I said, measure that opening and report back the area of the opening. Einstein.

 

[teddpage]

Emgo pods...sure. But a Uni-Filter...doubtful.

 

[sampson]

Pods would look waaaay sweeter! 8)

I have a set of carbs that are on a 305/ maybe 440 if you are interested. Would be easier than rebuilding yours. Pretty sure they would fit.
I also have the boots for the carb to air box, i have air boxes. I also have any random piece you are looking for. Shoot me a PM if you need anything!

 

[xb33bsa]

Like I said, measure that opening and report back the area of the opening. Einstein.

fluid dynamics... educate yourself...... report back