balanced carburetor

[300ec]

someone uses such a scheme on his carburetor?
prevent overflow of fuel during a dirty air filter
sorry for the bad language)

carb.jpg
is not balanced carburetor

carbb.jpg
balanced carburetor

[Neil E.]

If I understand the diagrams correctly, #1 is a normal externally vented float bowl. #2 is a float bowl vented only back to the inside of the air filter.

If the bike falls over, gas can get on the filter element and wash off the filter oil. When the filter is dirty you still wind up rich running and having less power.

Is the intent to prevent gas loss from the overflow tubing? You can put a loop in the overflow tubing up beside the carb then route it down past the swingarm.

[300ec]

when the filter is dirty - the mixture becomes richer and the power falls
with such a system the amount of fuel in the mixture is always the same

I can not describe it in English (

Such a system used in cars with carburetors
Many years ago in America)

[Neil E.]

OK, but nowadays we have bigger air filters and can use filter skins to extend the life of the filter, so it should not be that important.

[rosco]

I understand the theory but I would think that if it worked Mikuni & Keihin would be using it.

[MrBlah]

Originally Posted by Neil E.

OK, but nowadays we have bigger air filters and can use filter skins to extend the life of the filter, so it should not be that important.

when it's dry here by the end of the day my bike will barely idle because the filter is so clogged

[gasgasman]

The vent to the float bowl allows atmospheric pressure in which "pushes" the fuel out the jets.

Air filter condition has no effect on this.

[300ec]

Originally Posted by gasgasman

The vent to the float bowl allows atmospheric pressure in which "pushes" the fuel out the jets.

Air filter condition has no effect on this.

and when the filter is dirty - the pressure is reduced in the carburetor, and in the float chamber is equal to atmospheric pressure so that fuel consumption increases)

[GMP]

I understand your logic completely. In theory, yes its a good idea. In practice it can create more problems than it solves, like the flooding of the airboot. It would also be a good idea to connect the vents to the boot at multiple points to avoid blockage, same as routing one pair of the line up high and one low. This would mean an airboot full of holes and hoses. Just more complicated. In practice, if the filter is that dirty, it should be changed as soon as possible to avoid drawing dirt through it.

Where in Russia are you? I've been there a couple times, Moscow, St. Petersburg, Saratov and the Volga region.

[Jakobi]

Originally Posted by GMP

I understand your logic completely. In theory, yes its a good idea. In practice it can create more problems than it solves, like the flooding of the airboot. It would also be a good idea to connect the vents to the boot at multiple points to avoid blockage, same as routing one pair of the line up high and one low. This would mean an airboot full of holes and hoses. Just more complicated. In practice, if the filter is that dirty, it should be changed as soon as possible to avoid drawing dirt through it.

+1 My thoughts too. My filter after 100km ride last weekend was caked. Don't think it makes that much difference honestly.