Need float valve question(s) answered

[Guest]

Okay, my carb rebuild thread is DOA and I haven't had the float valve questions answered.
#1, How do you know if the valve is functional? Rather not put everything back together and find out a float valve needs replaced, is their a way to test?

#2, I have three float valves that are the same and one that is different. Is this acceptable? The one has a collar and tip is a little different, please inspect picture.

valve.jpg

[robbiem1961]

Take yourself a close look, with a magnifying glass, at where the float needle closes against the jet, there should be no discernable mark, lip or ridge that would allow petrol to get past, a fingernail will also pickup a step on the face...though in all honesty i can say that I HAVE not had to replace needles or jets on my gs's in all the 1000s and 1000s of miles i've ridden: if i were intending to do some serious mileage on her, for the sake of £20 a carb and peace of mind i'd fit new and be done with it

[rwnielsen]

One way I have used is to assemble all the float/needles in the carbs and invert the entire rack. Lightly blow into the fuel inlet. There should be no flow. Gently lift each float and you'll be able to feel/hear air flow which should stop when you release it. The ammount of pressure required is >1psi.
The needle vavles you show are both common. Personally, I would keep them with their respective seat assy. and not mix them up.

[cyclepat650]

One way I have used is to assemble all the float/needles in the carbs and invert the entire rack. Lightly blow into the fuel inlet. There should be no flow. Gently lift each float and you'll be able to feel/hear air flow which should stop when you release it. The ammount of pressure required is >1psi.
The needle vavles you show are both common. Personally, I would keep them with their respective seat assy. and not mix them up.

Ok, will try this and see how it goes, thanks for the input

[eil]

A close visual inspection will usually tell you what you need to know. (Make sure the pin is still springy too.)

The way to know for sure, however, is to do the fuel height test as described in the service manual.

The valve on the right is probably an aftermarket one. It will probably work fine if it fits the seat and the dimensions are the same.

[trippivot]

q #1 having the bowls removed and a test gasoline tank hooked up to your bank of carbs you hold the assembled float and needle up against the needle seat. (rubber band works great) and blow dry or wait a minute or 5 - if it stays dry it is working. gravity is all the fuel pressure required and more than that you will get a false failure.

upside down or right side up gas flows at the proper height and stops when needle is seated. --- it is when I am setting the float height I will blow with my mouth into the fuel inlet hose and set the height when it seals. lot like playing a bagpipe. look down all 4 and all should be nearly perfectly flat.

q #2 metal tip appears to be a mikuni VM and RS style rubber one looks like a keihin unit to me.