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  #11  
Old 07-02-2004, 11:57 AM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

     

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Originally posted by Faded
LOL, do you cover traveling expenses?


Maybe we can share the prize money, lol!!!!
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  #12  
Old 07-02-2004, 12:08 PM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

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Maybe we can share the prize money, lol!!!!
So you'll cover his breakfast expenses then?
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  #13  
Old 07-02-2004, 12:18 PM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

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So you'll cover his breakfast expenses then?
Yep, coffee not included!!!!
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  #14  
Old 07-02-2004, 04:09 PM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

Andrew awesome job Bro I think I am going to check my floats now.
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  #15  
Old 07-02-2004, 07:46 PM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

Great writeup and I now know how to set the float level but what exactly does the float do.

The float sits in the gas held by the bowl. Does it control the needle valve and does the needle valve modulate the gas coming in to the bowl from the tank ? Is this correct and is this the function of the float. So setting the float level determines when gas is brought in to the bowl. As it gets pushed/sucked out of the bowl the float opens the needle valve allowing gas to enter the bowl and keep it at a constant level.

I would guess that given all the bouncing around that a bike goes thru that the level of gas in the bowl can never bounce around to the extent that there is no gas available at the main jet to be used for combustion

Am I confused ?
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  #16  
Old 07-02-2004, 11:19 PM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

Quote:
Originally posted by TexasDirtNap393
Great writeup and I now know how to set the float level but what exactly does the float do.
Sorry for the confussion, maybe I should have clarified. The "floats" as the name implys are meant to float in the gas that is filling the bowl. As the fuel enters the float bowl it causes the floats to rise which push against the fuel inlet needle. Once there is enough fuel in the float bowl to raise the floats to the specified "float level" the the fuel inlet needle makes a seal with the fuel inlet valve seat cutting off the fuel supply. As the carb uses fuel and reduces the ammount in the float bowl, the floats are lowered and the seal is broken, allowing more fuel into the float bowl until the desired level is reached and the needle contacts the seat and shuts off the fuel supply.

Whew, I hope you can understand that.

Also, there is a small air pocket that resides on top of the fuel, that is why the carb is vented, and this is where atomospheric pressure comes into play. The atmospheric pressure is helping the force the fuel through the jets in order to equalize the pressure difference between the float bowl and the low pressure zone in the venturi of the carb. Atmospheric pressure, plus the weight of the fuel equals the amount of fuel pressure acting on the jets.

These questions are great, if you have more keep them coming! Let's help everyone understand.
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  #17  
Old 07-03-2004, 01:20 AM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

Faded, if you already haven't, I think you better open a bike shop!! I'm sure you will have a lot of customers because you're mechanical skills seem SO GOOD to me, really!!! great job you've done here!!!
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  #18  
Old 03-22-2007, 09:12 AM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

This is probably one of the best "how to" articles I have ever read!
thanks Faded!
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  #19  
Old 05-15-2007, 12:38 PM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

I have a question. I just tried to adjust my floats, which are shaped just like the ones in your pics, to 16mm. The previous adjustment was so far from 16mm when aiming for the very tip top of the float, that I began wondering if the very top of the float was the spot you were supposed to measure at. Just for the heck of it, I adjusted the float , setting the very top of it to 16mm, and it was quiet a huge change /adjustment to get it there! Something didnt seem right, -even with the carb completely upside down the fuel needle didnt seem like it was seated at all after this major float adjustment. I verified this by hooking a vacuum gauge to the fuel inlet and verified indeed the needle was not seating.

So I thought to myself, there's no way you measure at the very top of this float, but maybe closer to the linear line about 2/3 up, where its a normal "shape". I ended up adjusting my 16mm to line up with where the metal arms mold into the plastic float, and doing it this way gave me a sealed needle as judged by my vacuum gauge.

Im not questioning your writeup, Im questioning why did setting my float to 16mm the way you say cause some weird things to happen and actually hang my fuel pin up from seating?

Note= the bike spits whitish exhaust smoke at all times when reving from idle to full throttle in neutral (87 cr125)

Now i will go back to the garage and try this adjustment again.
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  #20  
Old 05-21-2007, 01:24 PM
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Default Re: How To Set Your Motorcycle Carburetor Float Level (more commentary).

Two things come to mind...and I'm not saying it's either of these but definitely something to check. First verify that the floats are installed correctly and not upside down (it could happen). Second, especially on a bike that old, how sure are you that someone didn't do you a favor and use a set of floats from a different carb?

It is also a commonly accepted practice to set the float level by having those 'mold lines' parallel to the gasket surface. Usually this is used in a pinch or if you can't obtain the factory spec. With your current setting how far off from parallel are you?
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