1982 KZ440 problems... carb?

I have a 1982 Kawasaki KZ440 LTD belt drive. I'm having problems in the low RPM's, my bike dies! HELP!!?

It started having problems yesterday, after I gave my friend a ride around the block. This is probably just an unrelated coincidence, but...

So, while we were riding, it started to get a little jerkey. Not too noticable, he didn't notice anything but I was dirving so I noticed. Then, I took off by myself, and the bike died! I got it into neutral and it started back up almost right away, but then I took it around a few more times to see what was up. It got worse and worse, eventually getting to the point where:

When I started it, it would start really.... slow. It would sputter and catch about .5k RPM's, and then slowly speed up to normal idle (about 1.5k). Then, if I didn't keep on the throttle, even in neutral, it would die. If I did keep on the throttle for about 5 seconds, then when I let off it would stay up in the 4-6K RPM range. It would stay there until I started to drive, and then after I was in first, when I hit the throttle, even before I let out the clutch, it would suddenly drop down to like 1k RPM and die. After many tries, I could sometimes keep the revvs up, shift into first, and keep the RPMs up high enough so it didn't die and I could take off, but then as soon as I had to shift into second (and so let off the throttle) it woudl die again. Towards the end, it would take a good 3 minutes to start back up again, I would jsut hit the botton over and over again and then randomly it would catch around 1K and the whole thing would start over, even the choke didn't help. In the middle of my riding around, I was trying to start it and it backfired a few separate times, making me think it might be a carb problem? The lurchey-ness kept getting worse throughout the day as well.

At this point, I put in fresh gas and things got a little better. Now it starts up right away, but still idles really slowly, and somtimes kind of stumbly. If it put it up on the centerstand and leave it in neutral, it will idle for about 1 minute before it dies. Also, I noticed that it has a hard time getting above 3k RPM's. If it stay on the throttle, it will go to about 3k RPMs and then hover, and if I really keep on the throttle it will shoot up to about 5k really fast. It seems to be fine in the higher RPM's (past 5k). But, if I let it hover around 3k for like 20 seconds and then let off the throttle, it will die. I ran it about 5 times this morning for the 1-2 minutes until it died, and didn't notice any backfires today.

Also, I am having a hard time getting the float bowls off. Even my stubby screwdriver is too long to fit under there, and I tried an offset screwdriver but couldn't keep enough 'upward' force to keep the head in the screw grooves. Anyone have a good way to get those bowls off?

I tried various things to fix the running problem, I changed the oil (I had thought that maybe the lurching was a lack of lubrication) and put in fresh gas, and changed the spark plugs.

Anyone have any idea what could be causing this?

People have told me that some tubes might be pinched (didn't see anything) and that my air cleaner might need to be changed (havn't looked into this yet, but that's next).
What else might this be?

thanks!!!

Hello, Will, and WELCOME to KZR!
We're glad you're here!

Would defer addressing carbs pending more investigation into other possible causes.

Did the problems arise suddenly on a bike with otherwise good performance history?

Could first experiment by running with petcock in PRI position and fuel cap ajar (not snapped down). Any change in performance? If not, let's go from there, as several more possibilities exist before resorting to the carbs.

Have valve clearances (gaps) been checked/adjusted to specs?

Is a factory service manual or other shop repair manual at hand?

Good Luck!

Several things to check: All electrical connections must be clean and tight; the battery terminals,the chassis ground, and the ignition switch connections.

Go to either Walmart or the local auto parts store and for about $7 get a can of "Seafoam" fuel additive. Follow the instructions on the can, this will help remove the varnish and crud from the gas tank and carbs.

thank you both for your replies.


I tried running it with the cap off, and it ran much, much worse. What does this mean?


The electrical connections look good, and everything sounds good when it is trying to crank over.

I bought a can of seafoam and will try to run it through tonight, which means most likely tomorrow because I am definitely way too busy!

New information--

I put in the seafoam, and tried to run it through-- In the process I found out the bike has a pattern, mhich may help diagnose the problem?


As I was running it through, I was just holding the throttle while it was up on the center stand. I had the throttle about 1/8 turn, and held it steady. What would happen is, the tach would get up to about 3k, stall, and fall back down to idle speed, then rev up to 3k again, and then fall back down, etc. If at any time I let off the throttle while it was falling, the bike would die (i.e. the only thing keeping it from dying when it fell most of the time was the fact that I was on the throttle). The whole 'speed up to 3k and then fall to idle (1.5k)' cycle took about 2 seconds.

what could THIS mean??

Have you pulled your spark plugs to have a look at there condition? What color are they? It would be cheap insurence to change them out and see if it makes a difference, you may be suprised.

I changed the spark plugs almost immediately. They looked okay, but I put in new ones anyways! The left one (of the old set) looked like it may have been starting to get a whitish deposit on the tip, but I ran the new ones for a few miles probably and there is no sign of whitening on it anymore. If anything they are a little too dark...

woliver wrote:

... tried running it with the cap off, and it ran much, much worse. What does this mean?...

Means time to call Guinness! :woohoo: :laugh:

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Any difference in performance if test-running with air filter temporarily removed?

Could also be fuel starvation problem.

And don't forget earlier suggestion about possibly too tight valve clearances.

Good Luck!