Hittin' on three ... kz1000e idle issue

rckz wrote:

#3 plug will foul if left idling too long. Black and sooty. If taken out and ridden, then shut off without idling, it looks fine.

Then the idle mix is too rich on #3.

I would check the air passages of the idle circuit and also the choke system which could be riching up that carb.

Have you tried taking the idle mix screw out and hosing the heck out of that passage with carb cleaner?

Post edited by: bountyhunter, at: 2008/01/28 17:09

rckz wrote:

...also checked the float level in #3. It was about 1-2 mm below the top of the bowl.

Might be a little high, as FSM for similar carb on '79 model calls for 2-4 mm below top of bowl. Are other carb float levels the same?

If not already done, would inspect pointed tip of pilot air screw for any damage. And might also experiment by swapping #3 pilot air screw with that from one of the other carbs. Also assure #3 screw is same as pilot air screw in other carbs (be sure it hasn't been replaced with a similar-appearing but incorrect screw.

Keep the faith!

How did you check the float level? The only real way to be sure it is right other than using a tube out the drain port as a Bernoulli tube, is to swap the float out of 4 to another carb. If you did it by measurement only that doesn't tell you if the float is "floating" properly as it is 27 years old you can't be sure how buoyant it is.

Assuming these are the 28 pumpers, my guess is the choke circuit isn't working right. Did you check it to be sure the plunger is moving?

If you are near a Harbor Freight they sell a $9.99 heat measuring device that looks like the remote key fob for your car. Works great and you can get a real idea of just how hot the headers are from one cylinder to the next. You can use that info along with color of the plugs to verify you are getting the carbs in the same amount of mixture area from one to another.

Post edited by: KZ_Rage, at: 2008/01/28 20:35

Patton wrote:

...might also experiment by swapping #3 pilot air screw with that from one of the other carbs....

Could also swap primary jets to see if problem stays with #3 or moves to the other carb receiving the existing #3 primary jet.

Another question -- pods or airbox? If pods, perhaps the pod is blocking primary circuit air intake entrance hole. Or maybe the pod filter is clogged or over-oiled. If pods, could remove #3 pod temporarily and re-test engine performance at idle rpm.

If airbox, would replace intake tubes from airbox to actually "enjoy" carb removal and replacement. And while suffering through yet another carb removal, would replace the pilot jets (they are inexpensive).

And remember to assure the choke plungers are doing their job when supposedly closed. And set the float height a smigen lower. And check the synch on #3. What the heck, let's go ahead and get #3 too lean and work from there.

Wow, guys. Thanks for all the suggestions.

Stock air box, by the way. No pod filters.

And I measured the float level with a clear tube stuck in the bottom of the float bowl. Seems consistent with the other float levels, but I can verify that and maybe raise the float a bit.

I'd say the float is possibly too high already if the choke circuit is working properly. Black sooty plugs from running at idle are either idling with the choke on for to long, a defective choke circuit or the floats are set too high which will also result in an overflow most of the time.

Still messing with it and getting closer to pushing the whole thing over a cliff.

Swapped chokes from 3 and 4. No difference. Lowered #3 float slightly. No difference. Still way too rich at idle on #3. Thought I might try the following, in no particular order.

Lower the #3 float some more.
Swap jets.
Swap slider/needle (CAN I swap sliders from one bore to the other?).
Raise the #3 slider a bit.

What ya' think?

i took the fuel line off mine the other day to change the filter, i walked over to a nice dead area of my yard and openedthe fuel petcock on the tank there, a whole crapload of goo came out, did this until clean gas flowed, changed fuel lines and filter afterwards.

I blew through the fuel line after connecting it in the carbs, while i had one by one opened the bowl drains with a clear hose going into a rinsed out battery acid container i keep around since my last new battery.

when doing this i noticed alot of water so i did this until no more was there (on each carb)

After doing this i started the bike and finally after a year it fired on all 4.

rckz wrote:

Still messing with it and getting closer to pushing the whole thing over a cliff.

Swapped chokes from 3 and 4. No difference. Lowered #3 float slightly. No difference. Still way too rich at idle on #3. Thought I might try the following, in no particular order.

Lower the #3 float some more.
Swap jets.
Swap slider/needle (CAN I swap sliders from one bore to the other?).
Raise the #3 slider a bit.

What ya' think?

Did you swap floats from one of the other carbs to this one?

Before swapping slides, check how much gap is between the slide and the throat bottom of the carb passageway like you did with the static balancing on the bench but now with the them mounted and cables attached. And yes you can swap but I never do unless absolutely necessary as I feel after this much time they have worn to match that body.

Post edited by: KZ_Rage, at: 2008/02/09 15:57

A new bit of data. I swapped carbs 2 and 3 (not pretty, but okay temporarily) and the problem moved to cylinder 2. So it IS the carburetor. Next, I noticed that if I blocked off the intake to the #3 carb (on the #2 cylinder) I got a fuel-wet hand, but not on the others. Seems to me the fuel must be coming from the accelerator pump circuit. Does that make sense?

Nevermind that last part. I disabled the accelerator pump. No difference. Other carbs will spew fuel also.

Post edited by: rckz, at: 2008/02/09 17:32

I just swapped floats, jets and needle valves. No difference.

Time to take that carb back down, grab the camera and post some pics of all the parts too if you can.
Look at the bright side, it's the carb and not the valves.

Post edited by: KZ_Rage, at: 2008/02/09 17:39