home made carb sync gauge part #

I'm not sure how to attach a file on here. Otherwise I would post my long winded building instructions and how to use it as an attachment. Since I can't do that I'll make this long and past it on here. You can already look at the few pictures I have of the this Rhube Golberg setuop in the previous replys.

How to make a manometer carb balancer

Some of the guys asked for a little help making up one of these manometers. I’ll give you a half a$$ed parts list and a little guidance.

PARTS:

Most of this stuff you can get at Home Depot or Lowes.

3 rolls of ¼” outside diameter vinyl tubing 20’ length. (Lowes sold them in 20’ lengths. I actually bought 6 rolls and ended up cutting a lot off. I think that 6ea 10 foot lengths should be fine. Whatever you think you would want for slack to be able to run the four foot vertical run on the board and then to the cylinders.)

6ea ¼” Raindrip double barbed connectors. (I used straight connectors. BUT you could use the 90 degree elbows and plan to mount them on the side of the reservoir chamber. This prevents the pipes from sucking up the inevitable bubble of air that remains in the reservoir.)

1ea ¼” raindrip Tee fitting. Used on cylinder #6. This allows the vacuum line to the fuel solenoid to maintain a suction. You could just suck real hard on the line and clamp it off during the balancing process. You make the choice, but somehow you need to keep suction on that line to keep the fuel flowing.

1 ½” diameter piece of black PVC pipe, about 6” long. (I used this size because it was what I had left over in the house. The reservoir does not need any particular volume. It just has to be a common place for all the tubes to connect.)

2ea 1 ½” PVC pipe end plugs. Or end plugs to match whatever size PVC you are using for the reservoir.

12ea 1/8” fiber insulated staples. To pin the vinyl tubes to the board.

Small container of PVC cement. I used the black stuff.

Some sort of flat surface to mount it all to. I used a 1”x 6”x 4’ pine board from the cheep pine lumber pile at Lowes. I threw a little paint on it to make it pretty, but not necessary.

JB Quick epoxy. Used to reinforce the tubes coming out of the reservoir. Or regular JB Weld if you don’t mind waiting overnight for it all to cure up.

1qt Automatic Tranny Fluid or Marvel Mystery Oil. You will only use about one or two cups. Get these also at your local Auto Zone.

TOOLS:

Tack Hammer
Drill to punch 6 holes in the PVC. (appx 3/16“ bit)
Hacksaw
T-square
Several Hemostats (If you tie your own flies for fishing, you will have some of these.)
Something to squirt the ATF fluid into the vinyl tubing to fill the reservoir.
Sharpie fine point marker. Not really necessary. But, if you want to throw some marks on the board to help line the carbs up a little, it doesn’t hurt. It also helps to put some numbers on the ends of the tubes where you are going to connect to the Valk’s intake ports.

ASSEMBLY:

Drill six evenly spaced holes in the center of your 6” long PVC pipe. I used 3/8” spacing on mine. Just leave enough room between the holes to wrestle on the vinyl tubing and still have enough room on the ends to squeeze on the PVC end caps.

Insert the raindrip ¼” connectors in the holes. They will pop through and then be loose in the holes. (unless you want to sand down the barbs on one end to go through the holes.) Apply a copious amount of PVC cement and let it dry. Be sure NOT to plug the inside of the connectors with the cement. Put the end caps on with the PVC cement and let the whole assembly dry. Both these two steps could take several hours to really cure up, so assemble it and go away for a while.

After the whole assembly has hardened up, slather some of the “JB Quick” epoxy around where the raindrip tubes are coming out of the PVC pipe. This gives you a little extra strength when wrestling on the vinyl tubing.

Connect up the six vinyl tubes to the newly made reservoir. A little drop of some ATF fluid or WD-40 will help them slip on easier

Take your board and place several reference lines across the board running from about one foot up to about three feet. I did mine with a T-square and ran them about one inch apart. This is not really necessary but kind of helps in the fine tuning.

Place the reservoir chamber at the bottom of the 4 foot board and attach it with the insulated tacks on each tube near the reservoir. Pull each vinyl tube tight up the length of the board and attach another row of tacks near the top of the four foot board. Kind of like stringing a guitar.

Place the vertical board with the PVC reservoir someplace low, like on the floor. Have the raindrip connector pipes at the apex of the PVC pipe (basically straight up) to get as much air out of the reservoir as possible during the next step.

Find something to squirt some of the ATF fluid into one of the tubes until that one tube is full, right down to the reservoir. Clamp off the tube about a foot from the end. (hemostats work good here) Then stick the vinyl tube into the quart of ATF. Rest the bottle up as high as you can above the reservoir and take the hemostat off.. Let gravity slowly siphon the ATF into the reservoir until you see fluid coming out of all six of the vinyl tubes. (This may take about ten minutes or so to siphon, depending on how high you elevated the container.) Let it fill up all the tubes until it is about 6-10 inches above the reservoir. Then pull the tube out of the ATF container. Keep that full tube up high until the fluid in that particular tube runs down and seeks it’s own level with the other five tubes. This will cause all the tubes to rise up to approximately 12-18” above the reservoir (Depending on how large a diameter PVC pipe you used to make that reservoir.)

Mark the vinyl tubes on the connection end (to the bike intake port) with a number. Furthest left pipe being #1 and furthest right being #6.…Duh! This just helps you keep track of the mess of tubing and where to connect them.

You now need to tilt the reservoir somehow, to get the tube ends away from the air bubble that is left inside the reservoir. The air gets in the line and will raise hell with the reading. I placed a 2”x 2” block of wood behind the reservoir to rotate it about 20 degrees.

You’re finished building! Now you have to figure out how to use it. There is a fairly relevant briefing on the “Tech Talk” board that talks about balancing carbs. it’s all good stuff, but not all of it will apply to you when using a differential manometer. This stuff is based on gauges to ambient, but the rest is relative.

CAUTIONS:

If any of the following things happen, you will cause a leak to ambient air pressure and the whole system will be sucking the ATF fluid into your intake pipes. This would not be good, although this should not destroy your bike or plug up your carbs. But it will smoke like crazy if the bike is running and possibly foul your plugs. The worst case scenario would be to let a large amount of fluid run into an intake port and into a cylinder head while sitting static. This could lead to “liquid lock” in a cylinder and be disastrous if you were to try to start the bike.

DO NOT let the hot exhaust come in contact with the vinyl tubing.

DO NOT hook up the tubes with the engine already running. Unless you have some sort of way to simultaneously connect all the lines at the exact same time (Or plug each line with the hemostats as your doing it.) the bike needs to be OFF when hooking up the tubes.

Make sure that your connections are air tight everywhere. Especially at the intake tubes.

Make absolutely sure that there are no leaks in your reservoir chamber or any of your lines.

You MUST have all six tubes hooked to the bike. None can be left disconnected. If for some reason you do not connect a line, you must completely PLUG it off.

And… (common sense stuff)… Do not use colored water, liquid soap, Aqua Velva, Chanell #5, mouthwash, honey, maple syrup, gasoline or any highly flammable liquids in stead of ATF or Marvel Mystery oil for a fluid.

Helpful hints:

The whole process is basically a pneumatic “Tug of War” between intake systems. If all are pulling equally, then you will have a balanced set of carbs.

#3 Carburetor is the MASTER carb and is not adjustable. You have to match all the other cylinders to #3.

If you get some air bubbles in the columns for some reason, just shut every thing down and wait a bit. You can expedite the settling process by strumming the stretched out vinyl tubes, sort of like strumming a guitar. Either that or pull the tube away from the board with one hand and snap on it with your other hand.

When you move one carb adjusting screw, all the others will be effected and will change. It takes a lot of playing around to get them perfectly matched. I was never able to achieve perfection this but it was very close. A small difference between these tubes is negligible and not worth chasing your tail over.

The adjusting screws are very sensitive. Do not put pressure on them with your screw driver tip while trying to adjust them. Use very light pressure and come off the screw to see what you accomplished after each turn.

Maintaining a constant RPM is not a problem with this method of adjustment. Most people who are adjusting with a gauge referenced to ambient air pressure are looking to seek a constant number and need to establish a reference by maintaining a constant RPM. Since the differential pressure will change equally on all six systems with varying RPM. All you are interested in is the minor differences between each carb. The factory recommends using 900RPM to adjust the carbs, but some people like to do it at 3000RPM to replicate a better balance at cruising speeds.

Light “blipping” or” goosing” the throttle is not a problem. You will get a distinct drop and rise shown on all the tubes when you do this but nothing drastic should happen. That is unless you have a weak walled reservoir that might collapse or crack. For this reason, I would NOT recommend doing a lot of revving, blipping or racing the engine while hooked up. A light clearing of the engine above idle should be okay.

Your on your own…So y’all be careful.