KZ400 Idle Problem

My wife recently got a 1976 KZ400 to join me and my 1977 KZ900. It idles a bit too low and kills at times. After looking at the manual, I found the idle adjustment but there is a cable that looks like it connects to the carbs, or should anyway. The cable is snapped. Am I correct in assuming that there is a cable that connects the idle adjustment to the carbs? What do I do to fix it? Do they sell these cables anywhere? Do I need to post a picture? Also looking to replace exhaust on the 400 - not for performance but because it is in need of replacement. Any suggestions on brands etc?

Demm,

On my 75 400 with KeiHins, there is a screw that pushes against the throttle assembly, twising it one way opens the throttle a little, twisting the other closes it a little. What carbs does the 76 have, Kei Hins? I may have an extra.

Thanks,

George

Yes it has the KeiHins. On mine, or my wife's I should say, the screw has a spring like cable that attaches somewhere underneath the carbs. That cable is snapped so the screw just spins with no purpose.

Yeah, the knob turns a spring cable to remotely turn the idle screw which is under the carbs. You will have to reach under and see if you can move the idle screw. You'll probably have to replace the idle screw with another screw or replace the whole screw/cable assembly. It should be easy to makeshift something.

Just wondering...the bike has recently had problems at higher RPM's. It really bogs down and won't accelerate past a certain rpm. Wondering if this could be attributed to the idle problem. Also noticed the left plug has some fouling on it and it is fairly new. Suggestions for a mediocre mechanic who needs things explained?

Check
Valve clearances (so easy on the 400)
Point gap and timing
Advancer unit
Power to coils
Compression

If that all turns up good maybe its time to take a peak into those carbs and clean em up and out and set fuel height (again, ridiculously easy on the 400).

Gotta love those 400's.

Peter

OK so I checked the points and they were fine as far as I could tell. Started to remove the carbs and noticed that the air cleaner ducts as well as the engine intake ducts actually had tape on them! Opened up the carbs and they looked decent. But the ducts were cracked and wrapped in electrical tape. The left side air cleaner duct was the worst. It actually had tape on the inside that was loose and sticky and gooey and quite a mess. Whoever owned the bike did a horrible job fixing that problem. Does it make sense that the left plug would be fouled/running rich because of this or would it be more attributed to the engine intake duct? They all have tape on them so I am assuming they are crap. Anyway, after a couple hours of searching, I found a website, (worldofpowersports.com) that you can just type in the part number from the kawasaki.com parts diagram and order it up. Also found a 10% off online coupon for this site. Pretty nice. I hope this fixes the problem but even if it doesn't, they needed to be replaced. Lemme know what you think.

Check Z1Enterprises for the parts too. If he doesn't have them on the web page call or email him, he probably has them.

double post\

Post edited by: OKC_Kent, at: 2006/05/22 23:12

(edit, you own a bike with points style ignition)

About the ducts, if there is only tape on the OUTSIDE of those ducts, then it is unlikely that the bike would run RICH (too much fuel) - if there was a leak in those areas, the bike would run LEAN (too much AIR).

After cleaning all of the ducts, inspect them throughly for cracks. If they aren't cracked, maybe the previous owner was just worried about them leaking and went about sealing them in a ridiculous manner, or maybe there really was a problem (and he went about fixing it in a ridiculous manner). If there doesn't seem to be any cracks, warm up the bike to a good idle, then spray WD-40 all over the boots and ducts and see if the idle changes. If it does, replace the ducts IN PAIRS (if one is bad the other one will be bad in a short manner).

Peter

Post edited by: newbikekiller, at: 2006/05/23 01:16

As mentioned, the ducts were cracked...all of them. And they were all taped. The left side air cleaner duct had loose tape on the inside which was all sticky and gooey and probably flapping around. I ordered all 4 new ones.

Hey I was wondering if you were able to pin point the problem with low rpm"s, my bike has the exact same problem, black spark plugs, bogs out really hard after 2nd gear, and won't go over 6.5 x1000 RPM