Carb issues I need some advice.

1975 Z1B
Top end has KZ1000 Cylinders
KZ900-A4 Carbs (three screws on top)
Pod filters
Accelerator pump
Main jet: 120
Pilot : 17.5


Hey guys I recently rebuilt the carbs include the Accelerator pump. I finally got the bike to start only issues now are i cant seem to get the idle to settle close to 1000 without dying out. It seems to be running real rich. When i rev the thottle it acts like its real bogged down. I checked the float levels I dont have a tool to check the exact height.I cant seem to adjust the air/fuel mixture screw enough to make it lean enough. I do all my adjusting after its been running for a few mins and the choke is completely off.

My guesses:

1) the float levels are too high
2) The jets

My questions are:

Its there a chart i could look at to go down a few jet sizes and see if thats the reason for the bike running so rich.

Its there a cheap and easy way to check my float levels that have drain plugs coming out the sides If so whats the proper height?

If this helps the orginally owner of the bike bought it from someone who rebuilt the entire bike to be a drag bike. (i.e. extended swingarm,rebuilt motor with KZ 1000 top end) The carbs aren't stock according to the jet sizes at least. These are much bigger.

I have been having almost exactly the same problems with my 79 1000 check to see if accelerator pump is working mine wasnt .the check ball between the float chamber and the pump was stuck and wouldnt let fuel into the pump.i got that fixed but it still acts like its runniing rich at idle and low speed.if i back the air screws out more than 1/2 turn it willl just load up and die.when ya figure it out let me know LOL.BTW im running stock 112 mains and 17.5 primaries.

The carburetors are not from a KZ900A4. Sound like a later (79/80) KZ1000 perhaps. Adjust the fuel level with a clear hose held next to the side of the bowl. You can find a 1/4" STRAIGHT vacuum fitting and insert it into the bowl after removing the screw and then just thread it in... it will drip just a tad but not enough to affect the reading. Hold the tube next to the outside carb with the rack exactly level and when gas fills the bowl, it will fill the tube. Knock out or blow into the tube to dislodge any air bubbles. The fuel level should be about 1/8" below the bowl gasket mating line.

I was just going with the picture on the Z1 website its the closest looking one to my carbs. But i did read on the other thread that i could try adjusting my fuel air mixture screw to 1/8th turn. Ill check the floats and that 1/8th turn and see what happens.

Question how long should the clear tube be to check it with?

dosent really matter how long it is ,,, needs to be higher that the carb bowl thats all

get a pic of the carbs on so they can help with the id of the carbs

LTD 76, stock jetting for the KZ1000A/B 79/80 pumpers is #15 pilot and #102.5 mains.

Perhaps this picture will help explain how the carb fuel level should be checked.

Thanks a lot wb. If it helps out any on your website in the tech stuff index the picture you have for the VM carbs is nearly exactly like that except mine have two fuel inlets between 1 and 2 and 3 and 4 with no vacuum fitting there at all. other than that it has the idle adjustment on the top side.

I checked the float levels and all seemed to be in the right range. There was a check ball in the third carb I took it out didn't think it was suppose to be there ( i could be wrong. I adjusted the fuel air mixture screw to 1/8th turn and it fired right up.

i can get it to idle at 1800 and it will go down to 1100 but it wont settle just kinda fluctuates.

Any ideas?

Thanks George i was going on what P.O.told me.still shouldnt load up at idle tho i guess i will check the floats and go from there.the carbs were cleaned and checked by local Kaw. dealer about 4 years ago.been stored dry until about a week ago.

If you have an accelerator pump, there are check valves in each carb bowl. These are visible on the bowl gasket mating edge. The check valve is a "bb", a small metal sleeve and a circlip. If the check valve isn't in place, that carburetor bowl will FLOOD with gas. In the #2 bowl, there is ANOTHER check valve which is down in the bottom of the bowl and not visible. If this valve is stopped up (and often is), no gas will get into the pump part and thus won't go into any of the the other carbs. The hole that feeds this check valve is VERY small. Most shops will not know how to clear this bottom check valve, if it is plugged up.