carb synch tool

[Guest]

Here is a pic of what I put together using ideas from other posts:

Vacuum gauge- $19 from Sears -$0 if you already have one

4 way valve($4)and 8 ft hose($2)
cut into four 2 ft pieces from a pet store that sells fish aquarium stuff

Four 5mm brass adapters(2 longer ones are for carb #2 and #3) ($15) from local Suzuki dealer

Worked pretty good, needle bounced 4-5 cm's and was easy to open/close the valve to check one carb at a time

You decide whether it was worth $40 total?? I can use a vacuum gauge for other vehicles anyway!

I could have purchased 4 of the permanent type adapters for $32 ($8 each) and saved time putting them on every time I did a carb synch

[Matchless]

Well done! If you want to stop the fluctuation of the needle just put a restrictor in the rubber line to the meter. I used a plumbing "urinal" tap which is just a 1/2" sleave with a small ball valve inside, adjusted by a screw from the outside. You can get the needle working properly in this way and again very inexpensive.

[Steve]

Nice job. Lurch. Hope it works well for you.

Just don't forget to check and re-check and re-check after making adjustments.
I have found that many times, when making adjustments, that all four levels are affected by one adjustment.
For example: You find that #3 (your master carb) is pulling 22 cm vacuum. You switch to #2 carb (my manual says that one should be next) and adjust it to 22 cm. Go back to make sure that #3 is still on 22 cm. Chances are that it's not. Keep going back and forth until 2&3 match, note the 'new' reading. Now move to #1 (again, my manual says that one is next) and adjust it to whatever 2&3 now read (unless you have one of the bikes that requires 1&4 to be about .5 cm higher than 2&3). Go back make sure that 2&3 are still there and match #1. Keep going back and forth with these three to make sure they read as they should. Finally check #4 to get it to match #1, then go back and make sure that 2&3 are still .5 cm lower than 1&4.

With patience and perseverance, you can do it, but that is way too much valve flipping for me. I'll stick with my mercury sticks for now. I have used the economy and better versions of the Motion Pro balancers. The economy version I would not recommend to anybody. It uses mercury, so is inherently accurate, but the lid over the mercury reservoir would pop off if you so much as looked at it cross-eyed, so I consider that unsafe and unacceptable. I recently had the pleasure of using the better version from Motion Pro. I don't know what the blue fluid is in the columns, but it works. You have to balance all four tubes to one source like you do analog gauges, but the included manifold and adjustment screws make it very easy. While in use, there is virtually no bounce in the columns. I like that. Some day I hope to see a Carb Tune in use to see what all the hoopla is over that unit.

Some time when you have the chance to see a four-column unit in use, I think you will see the difference and why some of us insist on it.


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[Matchless]

Steve,
You are 100% correct, I have actually built a home made manometer using ATF fluid in 4 tubes, but due to the size and just being itchy I built a similar unit with one vacuum gauge and experienced exactly that. I had to redo each adjustment many times before they were all the same, it is a bit of a nuisance unless you have a lot of patience. The easiest in practice is to be able to see all four vacuums and observe the changes simultaneously as you adjust any one. Even with fans the aircooled motor seems to get very hot with such prolonged adjusting.
Using a 4 set of vacuum gauges may be better as it also reduces the danger of mercury poisoning and spillage.

[Greg O.]

Using a 4 set of vacuum gauges may be better as it also reduces the danger of mercury poisoning and spillage

I remeber handling and playing with mercury when I was in school. Nobody thought anything of it then, and everyone had fun playing with it.

Like Steve said, it is a real balancing act to get all four the same reading. Adjust one, and the others change. You soon learn just about how much adjustment to make so as to match the others. I would recomend using 4 gauges so you can glance at them all at once. As you raise the vacuum on one cylinder, it will cause the vacuum to drop on the others.

Greg O