How To: Make a 2 bottle synch tool

Rick, the reason that you can consider the 2 bottles to share a reservoir is because the fluid is close to being incompressible. If the connecting tube is full of fluid, gravity does keep the level of fluid the same due to a siphoning effect. It kinda works like a toilet, once the fluid seals around the tube, all the fluid involved is going to be "flushed" to the other side, until the forces (i.e. air and hydro-static pressures) balance out, or there is no more fluid (and then it gets sucked into the engine.

Polock, I built mine and used it once, but the response was slow and I tended to over correct. The slow response is due to the amount of fluid it takes to change the height is too large due to the area of the bottle compared to the area of the connecting tube.

 

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Here's a working 4 baby bottle sync tool- - that works.
Water finds it's own level. . . the Romans figured that out.
I will start a new thread for my BB sync tool, that I built today.
Yes, it works, and I compared it to the 4 tube Manometer.
What am I doing in FAQ Suggestions anyway????????

 

YEAH! That's what I'm talking about...but I'm thinking about the four tube manometer for greater range.

 

I know.
I've engaged in this discussion before.

My opinion is that FOUR Bottle sources reduces accuracy.

I'd prefer to see someone Insert FOUR Hoses into One Common Bottle and Seal the Hoses tight.
Have a pinhole to break Vacuum.
A Fluid medium thick enough to respond to the Manifold Vacuum

Hook-up the Bike and see how that works.

 

4 bottles might reduce the response rate (dynamics), but not the accuracy. As long as there are no leaks, when you get a steady reading (statics), the forces have to balance out.

I'm also not sure that a 4 tube tool should have a pinhole to break vacuum. According to my calculations, you would need an 8.5 m tall column of ATF to compare the manifold vacuum to atmosphere (a 0.6 m column of mercury is sufficient). Otherwise, you'd be guaranteed to suck fluid into the engine. I think the bottle should be full and sealed and the hoses filled with fluid half way up their length (maybe 1m tall tubes for a range of 8.5 kPa) such that the tubes exchange fluid. Since we aren't ever trying to meet a vacuum spec, only compare the vacuum at each of the carbs, I don't think comparing the vacuum to atmosphere helps.

 

The underlying message from all these Posts is: Simplify.
Elaborately plumbed 4-Bottle manometers do not respond well enough to be accurate.
Using anything other than Mercury means the device cannot be compact.
The Fluid does not respond well enough to minor changes in vacuum.
The NEED to SEE a visual display of the four separate manifolds at the same level over-rules the accuracy that can be obtained without all the plumbing, bottles and fuss.

If you can overcome the compulsion to simultaneously view fluid levels all at the same height ...
The bottles
the fluids
the muss and fuss ...

can be eliminated by recording and adjusting the carbs to be in sync ... independently ... saving the time it takes to construct the 4 Bottle device ... and be done with it!

 

The sync adjustment from the Haynes book is basically as follows: Start by syncronizing one and two with the left side adjuster for the best balance you can get. Do the same for three and four using the right side adjuster. Now balance the pairs. This is done by adjusting the center screw balancing one and two to number three.
They are using four vacuum gauges with dampers. Since one and two are balanced you should be able to balance two to three. (No mention of four on the pairs balance. XJ650 & 750 Fours book 738 p.127)

 

I find it useful to install a valve or put a small c-clamp on the vacuum line. close it all the way and crack it open just a hair. This reduces any fluttering in the reading. I've been able to get really good syncs using an off the shelf vacuum gage this way. It's a "what I had laying around" replacement for the drop in beads that come with some store bought rigs.

 

Be sure to use the glass bottles, I tried the plastic version and they collapsed after a few minutes.

Also, I was able to slice off part of the stopper I bought and then use the bottle cap to tighten it and get a great seal.

 

if you sitting on the bike whick carb would be number 1...Is it all the way left or right..maybe other???

 

sitting on the bike, the one on the left is #1