Homemade Sync Tool - Need Input

[WMarshy]

So I've had plans to make this sync tool of a long time now and I finally got around to putting it together but it's not working right. I have restrict it's in the lines but I must have a leak because only after a couple of seconds of ruunning the fluid attempts to pass through the restrictive and go to #1 or #2 carbs. Is it possible the carbs could be so far out of balance it could empty one or two of the other lines?



Restrictor:


Anyone make one of these and use it with success?

[WMarshy]

So I've relearned a couple of things since my last post and thought I would share incase anyone else has interest in making their own tool.

1st, the tool in my picture would work just fine if my carbs were close to being synced already.

Unfortunately my carbs must be more than a few psi off. And when your way off you need a substantial length of vertical house so the fluid doesn't flow into the dominant carb. (14.7" of water is 1 psi IIRC)

2nd, if you have enough differential and one or all of the legs gives up all of it's fluid to the dominant leg you probably need to start with a bench sync.

3rd, there's a better alternative than the tool I pictured. It's a little more elaborate but if built properly it won't allow you to suck up any fluid.

This is the next tool I'm going to try.
http://youtu.be/0HfrHLmpHCY

[CaptonZap]

Well, Marshy, you are about half right.
1 PSI is 27.6799048425 inches of water.
Most vacuum gages are calibrated in inches of mercury, usually to 30 inches, which is 14.7 PSI, the standard atmospheric pressure at sea level.
Which means that if you draw 30 inches of mercury, you have close to a complete vacuum.


CZ

[DiverRay]

You should use the plastic valves from an aquarium shop for the restricter. You REALLY need a very small hole for the air. IF you use 4 valves, you can shut down all the way if one carb is dominant.
Me, I spent about $120 on a set of 4 gauges with adapters that will fit almost any multi-carb vehicle. But then, that was a few years ago as well.....

[WMarshy]

Well, Marshy, you are about half right.
1 PSI is 27.6799048425 inches of water.
Most vacuum gages are calibrated in inches of mercury, usually to 30 inches, which is 14.7 PSI, the standard atmospheric pressure at sea level.
Which means that if you draw 30 inches of mercury, you have close to a complete vacuum.

CZ

Thanks for the correction, I was second guessing myself on that number. It's been a while since I've had to convert between the two.

The main point is if your only 1 psi off you still need sticks that are 2 ft. I'm going to bet that it's easy to be more than 1-2 psi off if you don't start with a bench sync.

Unfortunately, the tool I made is only about 2 ft tall. I use to have 4 hoses about 6 ft long but one came up missing when I put this together the other day so I just cut two of the hoses in half. The good news is once I have them close and want to do a quick tune up I shoul be able to use this tool still.

[jimbyjimb]

A bit off-topic but is there an advantage to using a liquid or mercury style gauge as opposed to vacuum? I've always been pretty happy with the vacuum sync. Just curious if I'm missing out on something. Specs are + or - 2in/hg on the current multi-carb bike I own and getting my old XS to idle like a kitten with the vacuum gauge never was a problem.

That is a cool project, though. Great way to save $$$ instead of forking it out for an aftermarket fluid gauge. Good grief those things can get spendy.

[3Phase]

A bit off-topic but is there an advantage to using a liquid or mercury style gauge as opposed to vacuum? ....

Liquid-filled and mercury gauges never have to be calibrated and they can be easier to read than dial gauges.

On the down side, it's possible to slurp the contents into the engine. If it's just water or ATF it's no big deal. If it's mercury, try not to breathe. If you were working in the garage instead of outside, everything in it now has a fine mercury coating on it. Mercury's good for getting rid of yourself, children, insects, pets, small animals and people that never return things when they borrow them.

.

[WMarshy]

The only savings is the cost, the downside is the hassle of learning the tricks to it. Also something to consider is water filled are technically more accurate than mercury filled. If your within an inch on all 4 with a water filled sticks vs an inch with mercury filled sticks there is less psi differential because mercury is heavier per inch of column than water.

Those actually have #2 fuel oil in them because I didn't have anything colored I could use. Only issue is it smells when you spill it or get it on you.

[motoman]

Thanks for the correction, I was second guessing myself on that number. It's been a while since I've had to convert between the two.

The main point is if your only 1 psi off you still need sticks that are 2 ft. I'm going to bet that it's easy to be more than 1-2 psi off if you don't start with a bench sync.

Unfortunately, the tool I made is only about 2 ft tall. I use to have 4 hoses about 6 ft long but one came up missing when I put this together the other day so I just cut two of the hoses in half. The good news is once I have them close and want to do a quick tune up I shoul be able to use this tool still.

A nice, quick DIY there Wade. If your base fluid holding piece was larger with more capacity, meaning all tubes filled at least three quarters way up and fluid holding piece still has a bit of fluid in it, what you had happen wouldn't.

[Diskman01]

I built the SAME one about 4 years ago. Same problem as you. Never could keep it from sucking in air somewhere. Also one or 2 carbs really lifting the ATF quickly. I ended up just using one long 3/8 tube in a "U" shape with smaller tubes jammed into the ends of the single "U" that hook to the ports in the intake. I just sync the carbs in PAIRS now. I'm NOT using any restricters either. Just clear vinyl tubing.


ATF in the tube works fine for me. If you get one carb that's really pulling hard, shut the engine off and adjust the sync screw a bit and try again.

Once you get the engine synced, future syncings are MUCH closer and easier.

[motoman]

BTW folks, mercury used in a MANOMETER, and corresponding in.vac. calibrations associated with it IS what all other types of manometers,fluids, and calibrations are based on, not water. As has been and always will.

[CRXSi90]

I bought one of these. it will be a bit before I get to try it, but simple construction and might be an easier diy.

http://m.ebay.com/itm/331583591418

[Brent]

success

Anyone make one of these and use it with success?

Yes.
The tubing is very long. height I needed was 16 to 18 feet. Basketball goal including back board was not quite tall enough. It was too easy for water to pass peak and continue down into engine. I think this may have cleaned the carbon deposits out of cylinders. Side of house- about 2 stories was plenty high. I used 2 hoses and spliced some black vacuum hose to fit on carb connections (clear hose can melt through easily if it touches pipes etc.) Different diameter size of tubing affected how quickly level changed, but not vacuum or lift. I used water with a little food coloring added. Green, red or blue is easier to see than clear or light colors. 2 different colors, with one clear hose in each container, helped me keep up with which one Was high etc. No need to mark length or height of hoses, just adjust to match the two to the same lift elevation of the water. Directions in manual are clear enough as to how to use 2 hoses, gauges etc; match carb 4 to 3. 1 to 2. then 2 to 3. (1 moves with 2) check & repeat if needed.

I found medical tubing for oxygen patients to work well. It has some ribs inside the tubing designed to prevent kinking, but most any clear tubing from hardware or building supply could work.

For me; Cheap, easy to use, accurate. It did take me a long time to figure it out. I like it.
BUT - if you had to buy a ladder, if you fell off the roof, if you accidentally started a Christmas decorating project with red & green columns of water...
YRMV

Good luck wrenching
PS (I have got the Santa on Harley inflatable decoration removed from the top of my garage now)

[WMarshy]

Thanks, I ended using my mighty vac gauge on my vacuum tool. That got me close enough for now. I might drain the fuel oil out of the sticks and put some trans fluid in it. I'm going to get some better connections that go from the clear hose to the black automotive vac lines I hook to the ports.

[Gmac]

ATF (red)

I was going to point out that you could use ATF or kerosene in them which will not matter if it gets wheezed into the engine.

Personally, I bought one of those 4 dial gauges although I have yet to try it out. Space keeps shrinking in my shop out back but the side roof project is almost done.