Float valve seat problems

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Oct 30, 2002
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#1
Since I bought my bike last year it has had carb fuel level issues. I've replaced at least once every part I could think of: bowl gasket, float, float pin, float valve, valve clip, and more.

Finally this afternoon after trying my last option - a new float - and still having problems I decided to try something different. I put the float valve in its seat and held it up so that no fuel should be able to get past. However, sure enough I was getting fuel running down my hand.

I'm using a brand new float needle in perfect condition. And I've tried cleaning the brass seat with a cotton cuetip and toothpaste (mild abrasive). I've also seen posts about trying to tap a ball bearing but haven't found one the right size yet. My carb is off a 90kdx200, the keihin pwk-35, so the needle seat is not removable.

Any ideas would be greatly appreciated. Thanks in advance.
 
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#2
Try using a small strip of wet dry sand paper on the end of a Q-tip on the seat (it worked for me)
 
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#3
Thanks for the quick response. I have two more questions though:

Where can I find some wet/dry sandpaper, my home depot doesn't have any?

Also, did you try and put the strip on as a little cone (to hopefully give the seat a similar shape to the float needle tip)?

I'm a wet/dry sandpaper novice so any tips are appreciated.
 
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#5
Yup, I think we are taking about the same thing. You can also look up the specs at buykawasaki.com (90kdx200).

On my carb (I don't know if pwk35's from other years are different) the float valve sits in a small brass cylinder. When the fuel level raises the float, it moves the float valve higher into the cylinder - until the rubber tip seats - when it should shut off the fuel flow.

Unfortunately mine isn't completely shutting off the flow. It is a 13 year old carb, but I don't know if the rubber tipped float valve could wear out the brass contact point??? Right now I have no clue how it got this way, I'm just hoping its not so far gone I can't fix it.
 
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#6
Cut about an 1/8 inch strip of wet/dry about 1 1/2 - 2 inches long and place it over the end of the q-tip. Use your thumb and forefinger to hold the paper in place. Spray a little carb cleaner on the q-tip and stick 'er in the hole and sand away... It may take a few tries as the paper ussually rips

Have you tried dropping the float level?
I changed mine from 16mm to 17mm
 
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#7
Wibby, you're a savior. I've been dealing with these fuel level issues forever and your tip worked like a charm.

The bike still needs jetting, but now I know the jets and needle are the problem not fuel level.

My current jetting is stock slide, 150main, 42 pilot, cel needle in mid-clip. I'm running airbox mod, pc pipe and silencer, and boyesen reeds. Still smokes like crazy when I give it gas off idle so I suspect my pilot is rich (I dont have the room for a WOT chop). It doesn't like to pull the wheel off the ground easily but hopefully that's not far in the future.

Thanks again for the help, any other jetting suggestions are appreciated