80 KZ440B Carbs

Hey Guys,

Question on 80 KZ440B carbs. The PO changed the jets on the bike and installed velocity stacks. The bike is REAL cold blooded...I have to feather the clutch when taking off from a stop in the first 5-10 minutes of riding or it will die. I'd like to try pod filters and a change in the jets. Can someone confirm the appropriate jet size (main and idle?) with pods?

Also, the PO fabricated an exhaust can for the bike that is very loud and guessing creates less back pressure than stock. Is that going to be a real factor as well?

Thanks,

Paul

It's probably running WAY too lean. Install a stock airbox and some kind of decent exhaust and it will run a lot better and be rideable.

Can't go back to stock airbox...the bike's been significantly modified. Really hoping it can tuned with pods.

pjed wrote:

Can't go back to stock airbox...the bike's been significantly modified. Really hoping it can tuned with pods.

OK, understand. It can probably be tuned to run halfway OK. I have not tuned a 440, but with pods and a very low restriction exhaust, you typically would have to go up two or three sizes on main jets and maybe one on pilot (that's a guess). You may have to screw with needle position to try to get the needle taper to track the new airflow profile. It will definitely give you a new hobby.:laugh:

You may want to hang some kind of reasonable can on the exhaust. It will save your ears and be easier to tune.

According to a number of knowledgeable folks some of whom are/were Kaw mechanics, the KZ440 w stock carburetors is very difficult to tune without the stock airbox. Someone here on KZR installed some late model Kaw atv carbs & used a manifold w a single pod filter. I believe the topic was titled something like KZ440 bobber.

I wish Kaw had stuck with the piston-slide Keihin's. They are pretty reasonable to tune for pods and exhaust. They have a lot more jets that can be altered so the needles don't really have to be changed.

Thanks for the advice...guess I'll have to do some experimentation/trial & error. Bummed to hear that without the airbox they're hard to tune. I'll settle for 95% good. Really just want to address the cold bloodedness.

Any advice on a decent end can? Don't know what the stock one looked like but the one I have is a small megaphone style that sits under the right rear-set. I like the placement and look but want something quieter.

I have had several 400/440's with every variation of air cleaner and they have all ran great. i always figured it was one of the most forgiving KZ's in that respect. All of mine had stock exhaust or a mac 2-1 and they ran fine with stock jetting even dyno'd a 78' with no air filter and stock can and the jetting was very good with just a little lean between 5-7k. just make sure they are clean and that all of you other systems are working good.

I have no first hand experience w the 440. my disclaimer. hee.
Others have oft reported the difficulties of tuning the 440 for pods, including as mentioned some experienced vintage Kaw mechanics. Ya never know sometimes, though.

The 78 is a 400 w different carbs, so that example doesn't really apply.

the 78' 400 has CV32's and the 440 runs CV36's, very similar, almost identical and often confused. it is true i have not had one of my 440's on a dyno, which i admit takes away all the crosswind tuning stuff. but one of my 400 with a 440 head has the larger CV36's with cheap emgo pods and it also runs fine, in pretty much all conditions. i did get caught in a huge downpour a few years ago and it did not like sucking in water but i was not running any air filters at that time so that should be expected. now the older 400's with the CVB36's those really do like the factory airbox.
you might want to run over to kz400.com and read a few of the carb articles over there lots of good info.

That's interesting about the 400 carbs. The 440 is the only model that anyone has ever mentioned that seems truly unsuitable for pod filters. Those who mentioned it were adamant about it.