Carb vent line routing?

[Anonymous]

Ok, the carb vent lines ("T" between #1&2 and 3&4 carbs)... where should they go? The vent line on my carbs was looped from one to the other, connecting the vent of each carb together but not to atmosphere. Now that I think about it this does not seem right, if not could it cause the float bowls to overflow? Thanks.

[daveo]

They just hang down from the 'T', don't connect together

[Anonymous]

I don't think they are supposed to be together.

I have never heard of them being together. Mine and others that I have seen just hang over the back of the air box. If connecting them serves any purpose? I have no idea. Maybee some body bought the carbs seprate from the bike. They might have been put together for shiping. Then the old owner of the bike instaled them that way.

[robben]

Definitely need to breathe... and they should hang out in such a way as to be higher than the top of the bowls, from what an old Suzuki dealer/wrench told me. Mine hang back over the top of the airbox. If your carbs are flooding, there may be more to it than just this, but fix one thing at a time til you nail it down.

Robben

[Anonymous]

No, the old owner of the bike (or at least the last person to mess with the carbs) was a complete idiot. EVERYTHING is screwed up, out of place, missing, etc. The choke cable braket was on the #1 carb (instead of #2) and assembled wrong, it interfered with the petcock, the #1 float pin was so badly mangled by vise grips the float would only move if you put it together in just the right orientation, cv boots were sloppily thrown in and doubled over, torn etc. The throttle cable braket was replaced with a flimsy piece of sheet metal that flexed when you operated the throttle. It looks like they were taken apart and left for a long time then thrown together in a hurry to sell the bike. These carbs sit on a shelf now and I am using them for parts, I bought another set from a member here (Thanks!) and have done a quick cleaning/ replaced a few parts but I hooked the vents together like on my old carbs cause it seemed like the thing to do. I should have known better. Luckily the rest of the bike was NOT treated this way, only the carbs.

Now that I have these carbs that are in proper condition with new needle valves and properly adjusted floats, I STILL have gas overflowing from the carbs. This problem has trancended eight carbs in several states of disrepair with the improper vent line being the common denominator. Last night I had the bike running great, it idles, it revs, but it still dumps gas from all four carbs. When I get home from work I will pull the vent line and try it out again. If that dosent work I will bench test the needle valves but as I said, they are like new and the floats are set right AND this happens to all four carbs with both the old and new ones.

[Anonymous]

The best bikes are bought from stupid people.

I hope you got a good deal on it. You might have to sort out a few dumb problems, but he probably had to sell it cheap becouse he was too stupid to keep it repaired. Some of the best deals come from stupid people.

[KEITH KRAUSE]

The 2 floatbowl vent tubes should be open and routed under the seat.
They vent the floatbowls and fuel will not be drawn up into the jets properly if they are plugged or linked.
You say the carbs are overflowing. I assume they are overflowing out of the 4 floatbowl overflow tubes under the bowls?

[Anonymous]

No, actually the fuel flows from the air passage across from the air jet http://www.thegsresources.com/images...age%20hole.jpg

Although this last time it was a slow drip from the mouth of the carb and could have been coming from the main jet area possibly? When I revved the engine it did bubble from that air hole though.

[KEITH KRAUSE]

I wish I was more familiar with CV carbs.
I think the only things that can cause fuel to overflow, is dirt/rust interfering with the float needle valve, a worn valve, a damaged/missing
valve seat gasket, damaged/missing o-ring (some valves and seats use an o-ring), an incorrectly adjusted float height, a float that is stuck or punctured. I also don't understand why the fuel is'nt coming out of the bowl overflow tubes, that's what they're for. I do know that if the bike is on the sidestand the "tilted" level inside the bowls can somehow leak into the main bore, by-passing the overflow tube.
You say the old carbs leaked and the replacement carbs do too despite new valves. Are you certain that the valves are the correct ones?
What about the gaskets/o-rings I mentioned?
You say the carbs are clean, so that would eliminate any problem with the valves sealing due to dirt/rust?
What is the float height you set? This is with the bowl gasket in place?
Please don't take offense, but is there a possibility you installed the float valves upside down? The float should make contact with the valve's spring.
Is it possible the floats are upside down?
I say these things because you said the old carbs came in such a poor state and it sounds like you may have just copied what the old carbs were like when you re-built the replacement carbs. You have already found that the vent lines were screwed up, so anything else is possible.
That's why I question the use of correct parts or installation of parts.
Let us know how things go and I'll try to come up with more ideas if needed.

[Anonymous]

Ok, needle valves are clean and apear to be new, o-rings feel nice and fresh, float heght set without the gasket, floats and needles are right side up. I have checked and the floats and needles moved freely before I put things back together, no aparent binding there, no signs of the floats taking on fuel.

The needle valves look to be new, everything is shiny and fresh looking. I took them from the old carbs which were aparently rebuilt recently. I dont understand how/ why gas would be coming from that air hole. I will try to spend some time on it this afternoon and check back here tomarrow with what I find.