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Discussion Starter #1 (Edited)
When you set the float by measurement to 10/11 mm isn't it assuming that the float part itself is the the correct relationship to whe the slide is that the needle hangs on.
That would make the measurement with clear tube a essential way to double check the float/fuel level.
???????
Wonder if there is a measurement for float to place where needle mounts.

Or am I wacky:D
 

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When you set the float by measurement to 10/11 mm isn't it assuming that the float part itself is the the correct relationship to whe the slide is that the needle hangs on.
That would make the measurement with clear tube a essential way to double check the float/fuel level.
???????
Wonder if there is a measurement for float to place where needle mounts.

Or am I wacky:D
I don't have a clue what you are asking in the first sentence!

The float itself when placed on a flat surface should be horizontally alligned-- both float sides sitting on the flat surface and the brass connector straight across. Look it over and if it is twisted or tweaked in some way then you carefully get it symmetrical.

There is a tab in the middle of the float that is adjustable. with the carb upside down and level the float tab should be depressing the valve pin. Measure from the rim of the carb body to the top of the floats on each side. I believe it is 1.02 - 1.10 inches or 26-28 MM on my old style carb with round floats. This gets you close.

Use the clear tube method when the carb is on the bike and this gives you a good indication to where the fuel level really is when in operating mode. A sticky pin on the float valve is no good and if the float valve itself hangs up in it's cup this is also no good. You do not want one side of the float higher than the other when measuring.

GaryL
 
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I remove the carb when using the clear tube method, which I prefer, and use a long hose from the tank for fuel to the carb. That way I can hold the carb level when reading the hose/fuel level height. I do this with the bowl screws removed and just hold the bowl in place. That way I can dump the gas and make a quick adjustment and recheck.

I generally like to run my fuel level about 2mm below what the specs say. Particularly for off road stuff.
 

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Discussion Starter #5
I don't have a clue what you are asking in the first sentence!

The float itself when placed on a flat surface should be horizontally alligned-- both float sides sitting on the flat surface and the brass connector straight across. Look it over and if it is twisted or tweaked in some way then you carefully get it symmetrical.

There is a tab in the middle of the float that is adjustable. with the carb upside down and level the float tab should be depressing the valve pin. Measure from the rim of the carb body to the top of the floats on each side. I believe it is 1.10 inches or 10-11MM. This gets you close.

Use the clear tube method when the carb is on the bike and this gives you a good indication to where the fuel level really is when in operating mode. A sticky pin on the float valve is no good and if the float valve itself hangs up in it's cup this is also no good. You do not want one side of the float higher than the other when measuring.

GaryL
I remove the carb when using the clear tube method, which I prefer, and use a long hose from the tank for fuel to the carb. That way I can hold the carb level when reading the hose/fuel level height. I do this with the bowl screws removed and just hold the bowl in place. That way I can dump the gas and make a quick adjustment and recheck.

I generally like to run my fuel level about 2mm below what the specs say. Particularly for off road stuff.
Thanks for the fog clearing. I can be pretty thick headed at times.:D
 

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Or am I wacky:D
Not wacky.


Bending the tang on the float assembly is trial and error...until you get close to the 10 to 11 mm.




Using the clear tube confirms the actual fuel level in the bowl.




jb
 

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Not wacky.


Bending the tang on the float assembly is trial and error...until you get close to the 10 to 11 mm.




Using the clear tube confirms the actual fuel level in the bowl.




jb
Just for some clarification here. The carb shown is a new style carb. I don't know the specs on the float height for this carb. On my old style carbs that have round floats the manual says the height should be set at 26-28 MM or 1.02-1.10 Inches. You absolutely need to know which of the two style carbs you are working on before setting the float level.

GaryL
 
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Setting the float level is very confusing for me as well. I know that having it too high can cause the engine to run rich and vice versa. I am trying to set the height on my little bw because when kicking it it drips gas from the overflow and will leave a puddle where it sits. Can someone please CLEARLY explain how to set the float level?
 

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I will give it a go and will also welcome anyone who has better info to make corrections.

Find the specs for the carb on your bike and make sure you have the correct year, model and carb. If you are sure your float valve and seat are functioning and sealing properly you can set the float height with the carb off and float bowl removed. Place a ruler on the edge of the carb body and measure to the top of the floats on each side with the carb up side down and the float sitting on the valve pin, this would be the close position of the valve. There is a tab that pushes on the valve needle that can be bent to set the top of the floats to the correct height. If the top of the floats are too high according to the specs then your fuel level will be too low in the bowl when the valve is closed. You would bend the tab up to achieve the correct measurement. If the top of the floats are below the spec measurement then your float valve will not shut off the flow of fuel when the floats hit the top of the carb body. Bend the tab down so the top of your floats is at the spec measurement. Basically, the floats work just like the flushometer in your toilet. When you flush the float drops and when the tank fills up the float raises and at the very top, just before the water level reaches the overflow tube the valve closes and stops the water flow. If your bike is leaking fuel or your toilet keeps running all the time the valve is not closing.

JBFLA just posted some great pics showing his ruler on the body and the float here; http://tw200forum.com/forum/technical-help/9680-setting-float.html

Hope this helps

GaryL
 

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Thanks gary! So you take the measurement at the highest point of the float? I.e. the bottom of the floats when the carb is upside-down?
 

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Thanks gary! So you take the measurement at the highest point of the float? I.e. the bottom of the floats when the carb is upside-down?
UM, Maybe! If you mean the bottom of the float when the carb is on the bike, right side up then Yes. Go look at the picture in the link I posted from jbfla. His photo shows a reading of 10-11MM at the top of the float which is actually the bottom when the carb is right side up.

GaryL
 

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Thanks gary! So you take the measurement at the highest point of the float? I.e. the bottom of the floats when the carb is upside-down?
Yes, the top of the float.

Before you do any bending, check the condition of the tip of the float valve needle and the seat in the valve body to see if they are worn or have a build up of crud. This can also change the height of the float.




Below is a photo of the float tang...the part that is carefully bent to raise or lower the float.

I use a pair of heavy duty tweezers to do the bending (borrowed from the wife ;) ).

A mini pair of needle nose pliers should also work.

It's also important to keep the space between the tang and the two metal arms that hold the float needle the same.

As I mentioned before, just how much to bend it, is trial and error. You won't know the effects for sure until you do the clear tubing test...after everything is reassembled.

The actual level of the fuel in the bowl is the important thing, not if the the float is 9, 10, 11, or 12 mm high.

On the newer Teikei carbs the fuel level should be ~1 mm above the seam of the bowl and the carb.

Since the fuel level is above the seam, that is why you will get a fuel leak at the seam if you put the float bowl gasket in upside down.

(On the old style carb, the fuel level should be 7 to 8 mm below the carb body and bowl seam.)





jb
 
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Yes, the top of the float.

Before you do any bending, check the condition of the tip of the float valve needle and the seat in the valve body to see if they are worn or have a build up of crud. This can also change the height of the float.




Below is a photo of the float tang...the part that is carefully bent to raise or lower the float.

I use a pair of heavy duty tweezers to do the bending (borrowed from the wife ;) ).

A mini pair of needle nose pliers should also work.

It's also important to keep the space between the tang and the two metal arms that hold the float needle the same.

As I mentioned before, just how much to bend it, is trial and error. You won't know the effects for sure until you do the clear tubing test...after everything is reassembled.

The actual level of the fuel in the bowl is the important thing, not if the the float is 9, 10, 11, or 12 mm high.

On the newer Teikei carbs the fuel level should be ~1 mm above the seam of the bowl and the carb.

Since the fuel level is above the seam, that is why you will get a fuel leak at the seam if you put the float bowl gasket in upside down.

(On the old style carb, the fuel level should be 7 to 8 mm below the carb body and bowl seam.)





jb
Just as I said! you won't get this from a Yamaha site or off Google.

JBFLA can say in pictures what I try so hard to say in words. Thanks JB:cool:

GaryL
 
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Holy mother of all that is holy.........I am glad this is cleared up! :cool:

So, now we have learned that if your bike is upside down you can take your carb bowl off and check the height of your float that is right side up unless you live in Australia where your toilet flushes counter clockwise. Got it! :p
 

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A message to the Moderators.

All this talk and valuable discussions about our carbs with the 8X10 color glossy pictures supplied by JBFLA and I think we need to save this stuff for easy reference.

I can twist a nut or screw with the best of them but I can't finger fiddle this keyboard or computer to save my life.

How about a sticky, "All about Carburetors" or a technical write up with all of this great info for all to have easy access!

GaryL
 
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Holy mother of all that is holy.........I am glad this is cleared up! :cool:

So, now we have learned that if your bike is upside down you can take your carb bowl off and check the height of your float that is right side up unless you live in Australia where your toilet flushes counter clockwise. Got it! :p
LOL, Get with the program here Gisepi, we are talking motor bikes, not bicycles that you flip over to adjust the chain from many years ago.:eek:

That is funny though, so turds make skid marks in reverse down under?

GaryL
 

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All this talk and valuable discussions about our carbs with the 8X10 color glossy pictures supplied by JBFLA and I think we need to save this stuff for easy reference.

I can twist a nut or screw with the best of them but I can't finger fiddle this keyboard or computer to save my life.

How about a sticky, "All about Carburetors" or a technical write up with all of this great info for all to have easy access!

GaryL
Most of this is already in the Technical Write-Ups section of the forum, although in several different posts.:

Technical Write-Ups


jb
 

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Most of this is already in the Technical Write-Ups section of the forum, although in several different posts.:

Technical Write-Ups


jb
Yeah JB, I spent enough time there to get OT for my hours but there really is scant info on the older style TK carbs to be of much use to me and my pals who all have pre 2000 bikes. I posted dozens of good pics here but don't have a clue how to do the stuff you do with arrows and text in the photos. I am pretty sure my photo sharing is an open book and I have nothing to hide. Anyone who wants to use any of my photos is welcome to them.

GaryL
 

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I just wanted to make it very clear where you are to measure from. Thanks gary and jbfla. To get an exact measurement of the float level you need to tilt the carb 10°- 20° so the weight of the float does not push the needle down. Getting the float level right isn't really rocket science but it is a nice little trick to use the clear tube to make sure its around 1mm over the gasket. I have been doing it right but it never hurts to clear these things up. I thought i knew how to adjust valves until recently I learned that i was doing them too tight. That's one thing I should have cleared up but thankfully I never really hurt anything.
 

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I just wanted to make it very clear where you are to measure from. Thanks gary and jbfla. To get an exact measurement of the float level you need to tilt the carb 10°- 20° so the weight of the float does not push the needle down. Getting the float level right isn't really rocket science but it is a nice little trick to use the clear tube to make sure its around 1mm over the gasket. I have been doing it right but it never hurts to clear these things up. I thought i knew how to adjust valves until recently I learned that i was doing them too tight. That's one thing I should have cleared up but thankfully I never really hurt anything.
I think you are still not understanding how the float and needle valve seat function. As fuel fills the float bowl the floats rise and the adjustment tab depresses the pin which closes the valve and shuts off fuel flow. As you give it throttle the engine sucks fuel from the bowl and the floats go down opening the valve and allowing fuel in to refill the bowl and again the floats rise and shut off the fuel flow.

When you have the carb on the bench and up side down to measure with a ruler the weight of the floats should be depressing the pin all the way down, fully closed, and this is where you want it to take a measurement. You don't have to tilt the carb at all and instead want it as level as possible and you do want that pin pushed all the way down. If the weight of the floats does not push the pin all the way down then you have a problem and need a new valve and seat.

If you look at JB's photo showing the float tang, every float I have ever seen in an old style carb has that tang bent slightly down. This is a new style carb and it appears to be bent slightly up. It works the same but the new type floats are a great deal more boyant, the floats don't have as much up and down travel and the float bowl is not nearly as deep.

This is an old style carb and float showing the tang bent downward and the weight depressing the valve pin.



Here is the measurement on the old style carb body.



GaryL

Very important here! Keep in mind I am working with an old style carb that has round floats and is completely different in float height measurements than the new style shown in JB's pictures.
 
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