NooB needs some Float Level checking advice ...

when I first got her, I cleaned out the bowl and float needle ect and didn't go much further. Bike started up but would only run in choke. It was suggested that the pilot jets are probably clogged. These are the Mikuni BS34 CV carbs.

Started tearing down everything and I can tell someone has been in there before. The diaphragm mating surfaces to carb had gasket maker applied for a better seal and the pilot jet plugs were secured by using a punch on the side of the housing so they never come out. Used a drill and a screw to get the pilot jet plugs out. Gonna need to get atleast one of them new, so may get the rubber plugs that are used on the Suzukis.

Yes the Pilot Jets were clogged. Soaked them, ran a fine wire through them and blew them out. Cleaned everything and put them all back together. There is no information that I could find on how to set the Kawasaki carbs floats while the cover was out. Found a Suzuki rebuild tutorial and it said set the floats at 22.4mm, so I did as a starting point. Had to bend the Tang downwards to get the value up, as they were set much lower (which would bring the fuel level much higher). Anyway, on to the next step.

Started checking the fuel level when it was all put together. Set the carbs on the vise and positioned the tank above the table. Set up a clear tube on a drain and cracked it open, then opened the petcock. Fuel started filling up and stopped filling the bowls after a while. The height of the initial fuel level was very low (maybe 1/3 of the bowl full) but there was an air bubble in the tube. Raised the end of the tube higher until the bubble was pushed into the bowl, then lowered it back down (slowly blowing into the tube to push the bubble didn't work as the bubble would come back due to the lack of surface tension of gas) ... this is when the level climbed higher and settled closer to the top of the bowl; actually they all did the same thing an the fuel level settled between the screw head mating surface and the carb flange.

Did I do this right? Should the initial level be the correct one? The second measurement seems to be closer to where it needs to be but I'm afraid that may be a fluke.

I'm almost ready to sent these carbs off to be professionally rebuilt with the correct jets/etc. These currently have the stock jets (127.5/37.5) and the bike has the pod filters and a 4-1 header. I'm gonna have to tear them back down again anyways since I need to order choke seals, and most of the o-rings are at the end of their lives.

Rule of thumb with a square shaped float to make them parallel to the bowl mating surface. If they are round shaped floats then you'll need the exact spec.

Also most people flip the carbs over to measure the float height. That is wrong. The float needles have a spring loaded "shock absorber" that contacts the metal tang on the floats. So the proper way to set the floats is to slowly rotate the carbs until the floats contact the needles and stop moving. That is where you take your measurement or make your adjustments.

In reading what you did I suspect that you have them adjusted improperly.

Also just cleaning the jets is only have the task. You have to also clean the idle passages. you can bet if the jets were clogged so are the idle passages through the carb body. I like to take some electrical tape and wrap it around the straw that comes on the can of carb cleaner. That makes it fatter and will seal better in the passageway. Of course the jets have to be removed while doing it this way. Spray and confirm that you see the carb cleaner come out near the throttle butterfly in a good stream.

??? I don't understand the advice folks give about trying to set fuel levels with the carbs dry. The whole purpose of adjusting the float tangs is to set the FUEL levels, the float levels in dry carbs don't mean much if the resulting FUEL levels are not correct. I have not seen anything in my Kawasaki manuals that even mention setting dry float levels.

The ONLY way to accurately set the FUEL level is to use the clear tube method. It is the only method that ensures the FUEL level is correct. Keep in mind that the floats may not all weigh exactly the same and may not have exactly the same buoyancy. Consequently, setting all the floats to exactly the same measurement from anything without fuel in the carbs and the floats actually floating does not guarantee that the FUEL levels will be correct. This is why the Kawasaki Service Manuals don't even bother talking about setting the fuel level with dry carbs. The manuals are very clear and specific about using the clear tube method for setting the fuel levels. Ed

Yep, what Ed said. jd I think you did alright, though I'm not sure about blowing the bubble back through the tube. I think your second measurement is the more accurate one. If you're running stock jets and pods nothing is ever going to be right. You definitely need to rejet. I've never tried it myself but have read many threads of folks who struggled with this mightily. Best of luck.

650ed wrote: ??? I don't understand the advice folks give about trying to set fuel levels with the carbs dry. The whole purpose of adjusting the float tangs is to set the FUEL levels, the float levels in dry carbs don't mean much if the resulting FUEL levels are not correct. I have not seen anything in my Kawasaki manuals that even mention setting dry float levels.

The ONLY way to accurately set the FUEL level is to use the clear tube method. It is the only method that ensures the FUEL level is correct. Keep in mind that the floats may not all weigh exactly the same and may not have exactly the same buoyancy. Consequently, setting all the floats to exactly the same measurement from anything without fuel in the carbs and the floats actually floating does not guarantee that the FUEL levels will be correct. This is why the Kawasaki Service Manuals don't even bother talking about setting the fuel level with dry carbs. The manuals are very clear and specific about using the clear tube method for setting the fuel levels. Ed

FWIW my manual does give instructions for setting the dry float heights. It also gives instructions for confirming fuel level with the clear tube test, but it says nothing about which is more meaningful. Setting the dry float height is certainly useful for getting it in the ballpark, then confirm with the clear tube and tweak if necessary.

jackleberry wrote:

650ed wrote: ??? I don't understand the advice folks give about trying to set fuel levels with the carbs dry. The whole purpose of adjusting the float tangs is to set the FUEL levels, the float levels in dry carbs don't mean much if the resulting FUEL levels are not correct. I have not seen anything in my Kawasaki manuals that even mention setting dry float levels.

The ONLY way to accurately set the FUEL level is to use the clear tube method. It is the only method that ensures the FUEL level is correct. Keep in mind that the floats may not all weigh exactly the same and may not have exactly the same buoyancy. Consequently, setting all the floats to exactly the same measurement from anything without fuel in the carbs and the floats actually floating does not guarantee that the FUEL levels will be correct. This is why the Kawasaki Service Manuals don't even bother talking about setting the fuel level with dry carbs. The manuals are very clear and specific about using the clear tube method for setting the fuel levels. Ed

FWIW my manual does give instructions for setting the dry float heights. It also gives instructions for confirming fuel level with the clear tube test, but it says nothing about which is more meaningful. Setting the dry float height is certainly useful for getting it in the ballpark, then confirm with the clear tube and tweak if necessary.

Interesting. I have 4 different KZ650 Kawasaki Service Manuals. They each have a great deal of detail about the various carbs used on the KZ650 models, and they each describe the clear tube method in detail along with diagrams. None of them has any mention at all about setting the floats dry.

What model is covered in the manual you have? Is it a Kawasaki Service Manual or a Clymer or Haynes manual? Ed

Great info here, thanks to those who reaponded!
Is it the same fuel level setting height in the Mikuni vs. Other carb brands?
The only reason I did the dry upside down height setting was to get into the ballpark before I start doing the clear tube test

sorry if I offended anyone. My experience is with CV carbs on Honda mostly. I was referring to what I've done with everyone of them. Also in the KZ400/500/550 FSM I downloaded from this site, the KZ550H suppli,ment, dealing with the TK CV carbs, specifically sites, in two places, setting the float height dry at 27MM. Which, by the way, has the float horizontal casting level with the carb body.

Pagers 381 with a pictorial diagram with explicit instructions, and a table on page 402. And so far I have found nothing on setting up the CV carbs using a clear tube.

Perhaps Kawasaki changed their methods when they went to CV carbs.

Interesting. My manuals address Mikuni carbs. Do your manuals show both the dry method and the clear tube method or just the dry method? Ed

The manual I have shows the wet tube method for the smooth bores and only the dry method for the CV. Now that is in the supplement so they only refer back to the carb pages in previous sections but those only refer to removal, dis assembly and replacement of the carb rack.

Second manual down in the list on this page:

home.comcast.net/~loudgpz/GPZweb/Mnls/Mnls.html

650ed wrote:

jackleberry wrote:

650ed wrote: ??? I don't understand the advice folks give about trying to set fuel levels with the carbs dry. The whole purpose of adjusting the float tangs is to set the FUEL levels, the float levels in dry carbs don't mean much if the resulting FUEL levels are not correct. I have not seen anything in my Kawasaki manuals that even mention setting dry float levels.

The ONLY way to accurately set the FUEL level is to use the clear tube method. It is the only method that ensures the FUEL level is correct. Keep in mind that the floats may not all weigh exactly the same and may not have exactly the same buoyancy. Consequently, setting all the floats to exactly the same measurement from anything without fuel in the carbs and the floats actually floating does not guarantee that the FUEL levels will be correct. This is why the Kawasaki Service Manuals don't even bother talking about setting the fuel level with dry carbs. The manuals are very clear and specific about using the clear tube method for setting the fuel levels. Ed

FWIW my manual does give instructions for setting the dry float heights. It also gives instructions for confirming fuel level with the clear tube test, but it says nothing about which is more meaningful. Setting the dry float height is certainly useful for getting it in the ballpark, then confirm with the clear tube and tweak if necessary.

Interesting. I have 4 different KZ650 Kawasaki Service Manuals. They each have a great deal of detail about the various carbs used on the KZ650 models, and they each describe the clear tube method in detail along with diagrams. None of them has any mention at all about setting the floats dry.

What model is covered in the manual you have? Is it a Kawasaki Service Manual or a Clymer or Haynes manual? Ed

Well, it's the Kawasaki FSM for the KZ1000/KZ1100 that I'm referring to (a PDF file of which is available online). The same information is also in the Clymer books for these models. The carbs in question are Mikuni BS34CV.

Well I tried starting her up and it only started up using the choke and I was able to rude it up/down the street on choke only. Still can't run without the choke, so took them off again. Thought I had the float levels wrong and read somewhere here they need to be set at about 18-19 mm dry; that made the level too high and the carbs leaked out the bore haha. Set them back to 22mm.

Also had a issue with cyl 4 not really working. Swapped plugs with #1 and even swapped the wires due to same coil and still nothing ... bought new plugs just cos they are old. Spraying some ether on that pod filter seemed to liven it up.

Compression test showed 70/55/58/70 ... double checked the carb and set the pilot screws to 1-1/2 ... fingers crossed and will try again tomorrow.

^^ Timeline is everywhere haha, but they're sitting on the bench right now awaiting reinstall and start up