Carb lines, where do they go? and a mystery plug

[wakdady]

So I started taking my carbs out to clean everything up and hopefully get this thing running nicely sometime soon.
Here are the pics of what i am referring to;
Last time i did carbs this nozzle was going to the petcock or something, so i was surprised to see it not attached to anything. is it supposed to be this way? or does it hook up somewhere?



Second, this plug next to the fuel pump isn't plugged in to anything. Does anyone know what it's for? or where it should be going?


i did however, notice the jets were REALLY clogged, especially the main jets. No wonder why she would start right up, but the moment i gave it throttle it would die.

[Marsh White]

Second, this plug next to the fuel pump isn't plugged in to anything. Does anyone know what it's for? or where it should be going?

http://www.fjowners.com/index.php?topic=1321.0

[tqmx1]

The 2 white fittings were for Ca. smog now they just are vents. If you want you can put some lines on them and run them down with the other 4 vent lines. One way or the other it's not hurting anything. 

[wakdady]

perfect. so all seems fine then. I think i will just leave them as they are.
I will also use that plug to power something, like GPS or heated grips.

this raises another question, what bolts to this bracket?

[racerman_27410]

perfect. so all seems fine then. I think i will just leave them as they are.
I will also use that plug to power something, like GPS or heated grips.

this raises another question, what bolts to this bracket?

that bracket is used to mount the rear shock adjuster..... do you have an aftermarket rear shock ?


KOokaloo!

[andyb]

+1

[wakdady]

I do. It says White Power, I thought my bike was racist!
however, i dont know anything about it. such as spring weight and such. I've never ridden the bike though. it was in need of a clutch MC rebuild and the carbs were real dirty. only 19k miles though.

[Travis398]

Was it actually confirmed that the plug is used for emissions for the California bikes?

or was that just a theory?

[SlowOldGuy]

From the discussions that I recall (no direct experience with Ca emissions models), that connector operated a valve that the float bowl vent tubes were plumbed into.  The vent tubes are supposed to be attached to the 2 white plastic fittings between the carb pairs. 

On "normal" models the vent tubes were routed around the side of the carb heat shield and then behind the engine case where they were open to the atmosphere.

On emission models,  the vent tubes were first routed into an electric valve (which was switched by the connector in question).  The output of the valve went to the charcoal canisters.  I also recall the valve being able to shut off in the event of a fall to keep gas from flowing into the canisters, but I can't confirm any of this with actual experience.

And those other 4 small hoses?  They are NOT vent hoses.  They are air inlets for the choke circuits.

DavidR.

[tqmx1]

Dave, I beg your pardon, You better take your float bowls off again the four small lines run into the float chamber and no where else.

I have no idea where you got the idea they are tied into the enricher circut.

[Dan Filetti]

Dave, I beg your pardon, You better take your float bowls off again the four small lines run into the float chamber and no where else.

I have no idea where you got the idea they are tied into the enricher circut.

Wait for it...

[SlowOldGuy]

Dan,
Just trying to educate the public...(didn't have to wait long did you?)

Sorry Kim,
But you need to look at the float bowl gasket carefully.  

Check out the schematic of the carb.  The ports that those hoses attach to do not go directly into the float bowl, there is a slot in the float bowl gasket that connects this port to the fuel pickup tube for the choke circuit.  The resulting air/fuel mixture is on it's way to the choke output port near the throttle plate.

These tubes allow bleed air to enter the choke circuit and mix with the fuel that is being brought up from the float bowl.  Additional air for the choke circuit comes from under the diaphragm slide.

Why would there need to be redundant float bowl vents?  The 2 hoses between each carb pair provide adequate venting and they are ported into the top of the float bowl chamber where it makes sense to have a vent.  Putting a vent down near the float bowl gasketline is just asking for a leak.

Again, look up the carb schematic and it clearly shows that those ports are air intakes.

DavidR.

[SlowOldGuy]

Further:

Those ports "might" act as float bowl vents, but they would have to "breathe" through that tiny orifice in the bottom of the float bowl.  On second thought, that wouldn't work since that orifice is covered up with fuel.  Once fuel covers up this orifice, it would start pushing fuel out the small hoses.  The large vent hose prevents this from happening by venting the float bowl at the top of the chamber.

Plug up these 4 small hoses sometime when you've got the choke on and you'll see what effect it has on the choke mixture.

DavidR.

[tqmx1]

Dave, I was wrong (man I hate to admit it) I had George B. pull apart one of his carbs and sure enough it is bart of the enricher circut.

[SlowOldGuy]

Kim,
Didn't mean to beat you down man.  I did go out to the garage and pull a float bowl just to make sure.  :-)

Also, this isn't something that I figured out for myself.  The carb schematic in the service manual shows how these 4 hoses add air to the choke (enrichener) circuit.

I guess I get a little sensitive when someone questions my carb knowledge.  :-)

DavidR.