VM24 carburetors float height

I`m going to replace my float needles on my VM24 carburetors original was installed in a 650 engine 1980-1981 model.


I have two questions for making sure I have full control over these job.

1.
please see attached photo below (its not mine carbs on the picture, just for example), Is these the correct float height I shall have by using a clear tube?
The red line indicate where I think the level should be ?



2.
I want to adjust the bowl first time without using the clear tube (I will verify with clear tube after and make necessary tuning if needed).
What is the height I shall have with I use these method, please see attached photo (its not mine carbs on the picture, just for example):




I have added some real photo of my carbs:

Up turned you want 25mm from the mating surface to the float top to get you close when you do the clear tube method.
Clear tube you want the fuel level to be between 2 - 4mm from the main body mating surface. The higher the fuel level the richer the mixture.

You have different float bowls to usual Mikuni, they might be TK bowls, but doesn't make any difference.

Warren3200gt wrote: Up turned you want 25mm from the mating surface to the float top to get you close when you do the clear tube method.
Clear tube you want the fuel level to be between 2 - 4mm from the main body mating surface. The higher the fuel level the richer the mixture.

You have different float bowls to usual Mikuni, they might be TK bowls, but doesn't make any difference.

Thank you, when you saying mating surface, please see attached picture, we talking about the surface I have indicated with red ?
So 2-4mm under these surface, just want to double check so I`m 100% sure

Absolutely correct.

I meticulously set the float height dry, but when I checked the fuel level, they were all different. 1 or 2 were out of spec. So I reset the floats wet using clear tubing. To speed up the process, I made a carb stand for checking the fuel level. with funnel & tubing as a fuel supply. I only used 2 screws to secure the bowls. I also used a simple support for the floats so that they wouldn't get bent or mangled when adjusting the float tangs. Instead of bending the tangs, I flexed them x number of times. I set the fuel level in all four to exactly 3.0mm below the carburetor body. none of that plus or minus stuff for me.

Kawasaki KZ650 service manual. jarlef z650. the 1981 KZ650 pdf is in the Files section.

... Carb spec table from the pdf.

martin_csr wrote: I meticulously set the float height dry, but when I checked the fuel level, they were all different. 1 or 2 were out of spec. So I reset the floats wet using clear tubing. To speed up the process, I made a carb stand for checking the fuel level. with funnel & tubing as a fuel supply. I only used 2 screws to secure the bowls. I also used a simple support for the floats so that they wouldn't get bent or mangled when adjusting the float tangs. Instead of bending the tangs, I flexed them x number of times. I set the fuel level in all four to exactly 3.0mm below the carburetor body. none of that plus or minus stuff for me.

Kawasaki KZ650 service manual. jarlef z650. the 1981 KZ650 pdf is in the Files section.

... Carb spec table from the pdf.

Thank you for your advise to !

I was planning making a test support for the carb, earlier I mounted it to the bike each time, to much work

Thats the reason to do them wet. They can all measure the same inverted but due to different bouyancy they all measure different wet. As its the wet measurement that counts when in use, thats the way to do them.

Yes, agreed 100%. I made that discovery the hard way. :laugh:

Yesterday I installed the new seats and needles, I have taken photo of the old and they are wrong....
I made a quick support so it was easy to measure the height with the clear tube and then adjust.
The new needle and seat was working from first minute, before sometimes it has come gas out from one o the carbs for some seconds, but never under the testing yesterday.

I found it hard to hit the height on mm precision...

I ended up with:
1. Maybe 0.3-0.4mm over the body house.
2. On the body house
3. same as 1.
4. almost perfect 0,60 above the body house.

I measured 3,6mm from the body mating surface to the edge I indicate with the red lines on the photos, so my goal was to have 0,6mm above the edge (red line).

I hope these is good enough?



The bike was easier to start up and it was running on all four cylinders from the first start, before the 1 and 2 has started after I have given some throttle...
I need to run the bike more to get more answers....

With those measurements you are within tolerance on all 4 carbs. Good work.

Had a longer tour today, and bike behave so different respond quick to throtle and have much more power in low and midle range. Goes good in whole RPM range....

Seems like my unstable problem has been wrong needle / float height..,,

I’m so happy now need to start prepare new weekend tour

Thank you all for your inputs!