Vacuum Sync

[Dag]

I made this today to syncronize the vacuum between all six intakes.
The bike is running smoother. I cannot say if its only because of this (I did some carb and Dial-A-Jet adjusting as well)
Most of the "popping" disappeared after the desmog, but when downhill and "loose" throttle I could still hear some popping.
I've tried to get rid of this for a long time, but without success..... until today   

[SgtBunny]

Did you have to re-sync your carbs after this?

[matt]

was wondering since your invite to your shop how that worked out . while i have my airbox out i should look into building thanks

[Dag]

This was just a wild idea trying to get rid of the popping (a experiment).
But it works... Dont ask me why. My bike runs much smoother and I got rid of the popping.

This does not affect the carburetor synchronization since this is disconnected during the sync.

[SgtBunny]

Once I finish uninstalling my pair valve and do away with the vac feed on my petcock, I shouldn't need any vacuum lines just plugs on the carbs, correct?

[Rocketman]

Once I finish uninstalling my pair valve and do away with the vac feed on my petcock, I shouldn't need any vacuum lines just plugs on the carbs, correct?

That's correct.

Dag, did you have yours plugged before?

[Dag]

Once I finish uninstalling my pair valve and do away with the vac feed on my petcock, I shouldn't need any vacuum lines just plugs on the carbs, correct?

That's correct.

Dag, did you have yours plugged before?

I suppose you mean the rubber caps on behind the intakes. Yes.. It would not run without.

[Mikey]

Do you run a Cruise Control Dag? Could you just add another T (like the one for the fuel line) for the Cruise?

[Rocketman]

Dag, did you have yours plugged before?

I suppose you mean the rubber caps on behind the intakes. Yes.. It would not run without.

Yeah, bonehead comment du jour on my part.
I was trying to ask if it was desmogged, and had a mental shutdown while typing.

[hubcapsc]

Dag, did you have yours plugged before?

I suppose you mean the rubber caps on behind the intakes. Yes.. It would not run without.

Yeah, bonehead comment du jour on my part.
I was trying to ask if it was desmogged, and had a mental shutdown while typing.

I learned from Dag that European Valks were never smogged in the first place. The places where
smog stuff hooks into their engines doesn't need capping off, they were cast with no holes. I guess
the intake runners must all have ports, since they at least need the vacuum one...

-Mike

[Dag]

Posted by: Mikey 
Do you run a Cruise Control Dag? Could you just add another T (like the one for the fuel line) for the Cruise?
I dont have a cruise control, an I have no idea about how its installed

Posted by: Rocketman
I was trying to ask if it was desmogged, and had a mental shutdown while typing.

I have a US model and it`s desmogged. Did it last winter.

[Warlock]

Once I finish uninstalling my pair valve and do away with the vac feed on my petcock, I shouldn't need any vacuum lines just plugs on the carbs, correct?

I went to Lowes and bought some 5mm srews. Can't remember the length, but as short as I could fine. Un-screwed the pieces in the intake tubes, added some of the wifes finger nail polish on the threads and screwed them in. Kept my other pieces and put them back in if I think a syn is needed. No more worry about the rubber nipples cracking anymore.
David

[John U.]

Dag, did your vacume harness have any effect on idle or gas mileage?
Seems like it would have the effect of moderating vacume pulses. It's certainly an interesting experiment.
Please let us know if you find any additional effects as you continue to run with it.

[Dag]

Dag, did your vacume harness have any effect on idle or gas mileage?
Seems like it would have the effect of moderating vacume pulses. It's certainly an interesting experiment.
Please let us know if you find any additional effects as you continue to run with it.

It has no effect on gas milage. The engine are running smoother.
Does anyone know the "task" of pulses. What is the purpose?

[Wildman]

Thoughts on how it works.

The tubing manifold connected to the vacuum ports lets air in after the carburetor slide, reducing the vacuum on the pilot fuel circuit.
This would lean out the fuel/air mixture at idle.

If this is making the engine run smoother/better;
The pilots are too large.
Or the vacuum sync is not uniform to start with
What kind of sync. tool are you using ?

[Dag]

Thoughts on how it works.

The tubing manifold connected to the vacuum ports lets air in after the carburetor slide, reducing the vacuum on the pilot fuel circuit.
This would lean out the fuel/air mixture at idle.

If this is making the engine run smoother/better;
The pilots are too large.
Or the vacuum sync is not uniform to start with
What kind of sync. tool are you using ?

#38 SLOW JETS (STD IS #35) AND #95 MAIN JETS (STD IS #100)
+ Dial-A-Jet Fuel Induction System

Here is my Sync setup
Carb Sync Honda Valkyrie


Google: vacuum pulse balancing system

[RLD]

nipples cracking

Now that can be painful. 

Seriously though, 5mm bolts with a couple of washers (to not restrict air flow) work great, never leak, and are easy to change when doing a carb sync.

[Rocketman]

The tubing manifold connected to the vacuum ports lets air in after the carburetor slide, reducing the vacuum on the pilot fuel circuit.
This would lean out the fuel/air mixture at idle.

There is no opening to ambient air.  It's providing a path from one intake to each of the others, and still retaining the vacuum for the stock petcock.  It should not lean it out any, except on the micro-scale of between the fluctuations.  Of course, I doubt that the hoses are large enough or short enough to have a major effect on something so transient.
Sounds like it was a very minor effect that was just enough to solve the problem.

[Rocketman]

Posted by: Mikey 
Do you run a Cruise Control Dag? Could you just add another T (like the one for the fuel line) for the Cruise?
I dont have a cruise control, an I have no idea about how its installed

He's asking about the vacuum operated Audiovox.  It simply requires a vacuum source.  Yes, another T would be perfect for that.

[Rocketman]

Dag, did your vacume harness have any effect on idle or gas mileage?
Seems like it would have the effect of moderating vacume pulses. It's certainly an interesting experiment.
Please let us know if you find any additional effects as you continue to run with it.

It has no effect on gas milage. The engine are running smoother.
Does anyone know the "task" of pulses. What is the purpose?

No purpose.  It's a side effect.  It's the fluctuation in vacuum caused by the intake valve opening and closing, and shown on the carb sync setup if you don't have a restrictor valve installed.

Mark