Topic: Fuel level in float bowl

[Duke McDukiedook]

The physics will work if both areas of your fluid are both exposed to atmosphere (this is referring to the clear tube method).
It sounds like your suspect float(s) is/are not closing the valve to shut the pressure of fuel off.

[Jimray23]

If the gas in the tube is at a different level than the gas in the bowl, there is a blockage or restriction not allowing flow into the tube. It could even be a restricted vent.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[Jimray23]

If the gas in the tube is at a different level than the gas in the bowl, there is a blockage or restriction not allowing flow into the tube. It could even be a restricted vent.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

Or your carbs are not level

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[tlbranth]

Tried to run the bike.Had multiple problems. I don't like the 6mm number. I think the level should be lower. So right now I'm setting #1 by the manual and using the bottle method, set the others the same. Then I'll try again.

[Jimray23]

And then there's the other possibility that the 10mm is part of the setting with the clear tube.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[tlbranth]

The physics will work if both areas of your fluid are both exposed to atmosphere (this is referring to the clear tube method).
It sounds like your suspect float(s) is/are not closing the valve to shut the pressure of fuel off.

Nope. There's something else at play and I'm done screwing with it. With the bottle method I can see wtf is going on and there's no surface tension, bubbles or anything else going to mess up my reading.

[tlbranth]

If the gas in the tube is at a different level than the gas in the bowl, there is a blockage or restriction not allowing flow into the tube. It could even be a restricted vent.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

Or your carbs are not level

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

I leveled the jig in both directions with shims.

[Jimray23]

Have you checked for restrictions everywhere? In the drains and vents?

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[DaveBarbier]

I liked DaveBarbier's idea of a clear plastic bowl and became frustrated with not trusting what I was seeing. So I went dumpster (recycle bin) diving and came up with a smallish plastic bottle. I cut a section from the bottle and after removing #1 bowl and spring clip, set the bottle bottom on a block under #1. It was an eye-opener. The level was at least 10mm different from what I saw with the clear tube. I adjusted the float 'til the level was 6mm below the outer part of the body flange at it's low point. Then I did the same with #4. This setup didn't work on the middle two carbs because the bottle was too big. But I revisited the recycle bin and came up with an empty bodywash container from Costco. It's a triangular shape and fits well on all the carbs. I adjusted the middle two carbs to the 6mm setting too.
This setup, I think, is better than the clear tube method because something happens to give false readings with the latter. My physics background tells me it should work but I think someone with an engineering background and knowledge of material properties would know that pure science don't allus work in the real world.
An advantage to the bottle method is that you don't have to keep removing the bowl to make an adjustment. The bad is: you'll have spilled fuel everywhere - hence the kerosene ploy.
My bike runs rich which is why I chose 6mm. From what Flybox1 said, it should be 3mm. But I'll give this a try and see how it goes.
I will post some pics on another thread of my dimple fix. I think it's a good, easily repeatable, fix. And trust me, those innocent looking little marks are deeper than they look and will hang up your float and make the carb overfill & leak.

Cool! I was thinking of a fuel safe plastic but of course a recycle bin find is perfect, only has to last for the test then back to the recycle bin home

[tlbranth]

And then there's the other possibility that the 10mm is part of the setting with the clear tube.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

Sorry, don't follow.

[Jimray23]

And then there's the other possibility that the 10mm is part of the setting with the clear tube.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

Sorry, don't follow.

Perhaps the actual fuel level should be 13- 15mm below carb mating surface and the clear tube shows different.
For instance, the jets on my mikuni carbs stick down into the bowls aproxamately 15mm past the mating surface of the float bowl.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[tlbranth]

That's the problem. I don't know what the actual level should be. So I'm going back to basics: set the float with the tool, then measure the fuel level.

[DaveBarbier]

Why isn't the typical 3mm below the seam good? You do not want the level to be even with the jets, that's far too low. It'll be like sipping from an almost empty cup of coke at the movie theater.


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[DaveBarbier]

Oops, I posted a question in the wrong thread, haha. Just deleted it. Carry on


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[Jimray23]

Why isn't the typical 3mm below the seam good? You do not want the level to be even with the jets, that's far too low. It'll be like sipping from an almost empty cup of coke at the movie theater.


Sent from my iPhone using Tapatalk

Because the levels in his bowls were different than the levels in his clear tubes.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[Jimray23]

But then again, maybe the 10mm difference is the space that the floats took up. Meaning the floats displaced enough fuel that when the bowl was removed to check the level it only appeared to be 10mm low.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[TwoTired]

I have to admit,  I'm totally confused why the clear tube sight gauge process doesn't work for you.  All fluids will seek to self level in whatever shape container they are placed in.  The tube is just a container extension.  Earth's gravity is what does all the work.

If you can't get the sight gauge portion directly against the outside of the bowl, use a bubble level to transfer the meniscus in the tube to the bowl's location.

If the bowl is having issues filling, the vent system is suspect, or the supply line is blocked.  The float bowl is just a reservoir.

What am I missing?

[DaveBarbier]

But then again, maybe the 10mm difference is the space that the floats took up. Meaning the floats displaced enough fuel that when the bowl was removed to check the level it only appeared to be 10mm low.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

Well, that's not how one checks to see what level the fuel is in the bowls. If you remove the floats of course it will appear the fuel level is lower because the floats displaced fuel.

Isn't most of this thread pretty much saying how the clear tube method wasn't working for him? Meaning the clear tube process for tlbranth was giving a faulty reading. The 3mm below the seam is still valid regardless if the clear tube process is performed incorrectly or gives a false reading. 3mm is the goal, it's up to the user to attain that.

[tlbranth]

I'm not sure where the 3mm number comes from. But if I set the float using the 26mm gauge and then use my bottle level method, the level is a lot lower than 3mm from the top.

[TwoTired]

I'm not sure where the 3mm number comes from. But if I set the float using the 26mm gauge and then use my bottle level method, the level is a lot lower than 3mm from the top.

Is this with the original float valves?
Are the valve seats fully seated in the car body?

Brass floats?  In good condition?
The Vent system clear?

Are you compressing the float valve spring pin when making the 26mm measurement?

[Jimray23]

Good luck, i will not bother you on this subject anymore. There is several different ways to get where you want to be. But if you set the fuel level different to adjust a/f ratio, well lets just say that might not be the best way to go.
Again good luck.

--------------------------------------------------
Jim
1979 kz1000b ltd
    stage 3 cams
    pod air filters
    4-1 open exhaust(no muffler)
    full rewire
    dyna-s ignition
    dyna 3 ohm coils

[BobbyR]

OK, I think I see what is going on with the clear tube method. When I use the clear tube method I can vary the level in the tube by moving it away from the carb. Looking at your test rig you have the tube away from the float bowl and it will be at an angle caused by the wood. The tube needs to come out of the float bowl and tight against the carb body for a proper reading.

[DaveBarbier]

OK, I think I see what is going on with the clear tube method. When I use the clear tube method I can vary the level in the tube by moving it away from the carb. Looking at your test rig you have the tube away from the float bowl and it will be at an angle caused by the wood. The tube needs to come out of the float bowl and tight against the carb body for a proper reading.

The physics says that the tube can be down the block for all it cares. It will always be at the same height. A water level is a very old tool. I've used clear tubes filled with water across my yard to level out a place for sheds, patios, concrete pads, etc.

One thing to note is that when doing the clear tube method, fuel can enter the bowl, but not leave the bowl. If you have the tube low and then turn the fuel on and the tube fills up and then you raise it, the fuel will raise inside the bowl past the floats. Just saying. I think air bubbles caught in the end of the tube cause an issue. If I suspect an air bubble in the line I start over with the bowl empty. Put my finger over the tube end and fill the bowl with fuel. Then release my finger and the pressure of the fuel filling the tube pushes any air bubble out.

That's all I can think of.

[tlbranth]

Is this with the original float valves?Yes

Are the valve seats fully seated in the car body?Yes

Brass floats? 3 brass, 1 plastic In good condition? Yes, no leaks
The Vent system clear?Yes

Are you compressing the float valve spring pin when making the 26mm measurement? No, just 'til it touches

[TwoTired]

Have you checked the float valve spring pins for movement and equal pressure when depressed?