Another version of the homemade manometer

[eastern]

Just thought some of you who take satisfaction in making homemade tools would be interested. I saw this on the VFRD boards and thought I would provide the link to it. I am not quite sold on having to use 4 hoses so I will let everyone else debate whether the original homemade manometer which balanced 2 carbs at once and then against the other 2, or if balancing all 4 carbs at once is better. Have fun.

http://www.vfrdiscussion.com/forum/lofiversion/index.php/t16200.html

[spyug]

Thanks for the info and posting the link. Quite a simple rig.

I made one of the 2 tube models which I use to synch the carbs on the XS. It works well so I would think this 4 tube should also. I'll need to read up on the proper metholodgy for synching 4 carbs as I believe they need to be paired and I think one pair (2-3 maybe) are set differently than the others. Can someone elaborate?

Thanks again,
Spyug

[lurch12_2000]

Thanks for the info and posting the link. Quite a simple rig.

I made one of the 2 tube models which I use to synch the carbs on the XS. It works well so I would think this 4 tube should also. I'll need to read up on the proper metholodgy for synching 4 carbs as I believe they need to be paired and I think one pair (2-3 maybe) are set differently than the others. Can someone elaborate?

Thanks again,
Spyug

I don't believe that they have to be measured in pairs, but adjustments may affect the adjacent carb(s). You would just read all four initially if you had the 4 tube version tool and yes the #2 and #3 should be slightly lower. Example of my GS1100G readings were #1 - 23cm, #2 - 23cm, #3 - 22cm, #4 - 23cm, at 2700-3000rpm, but I'll have to go back to my notes. I didn't bother to adjust because they were so close and I'd probably make it worse by mucking around. Keep in mind I used a single vacuum gauge with a 4 way valve and hoses and tried to pick the median spot of the fluttering needle(21-25cm or should it be the highest reading ?). Others on the forum may give what the manual says for specific models and further advice.

[Muser3]

another manometer

Very clever! Gotta try this one!
Lee:-D

[trippivot]

on CV carbs the vacuum height will self center and all you can do is equalize.

the mechanical carbs you can set at 10 cm or 15 cm or 18 cm wherever you like the vacuum height, which even if equal on all 4 cyl. may not run very well
unless at the specific height for your local atmosphere.

all the old honda books show how to make your own manometer set out of a jar and tubeing. you can use water as to not ingest weird fluids in through the bike.

that mercury is bad to breathe

me personally I have always wanted a set of suzuki brass and glass with steel balls that hover inside. $600.00 +

I have a set of bouncing dials that I recalibrate every time. I can get them within 2 cm easily, closer if I care.

[tkent02]

With this style manometer there is no height, just balance.
It's not vented, the height is fixed by the quantity of water.
All you can do is adjust each carb relative to the others.

[Suzuki_Don]

With this style manometer there is no height, just balance.
It's not vented, the height is fixed by the quantity of water.
All you can do is adjust each carb relative to the others.

Do you need height as well as balance? Could you please explain? What are the difficulties with tuning carbs with this set up?

[Suzuki_Don]

Do you need height as well as balance? Could you please explain? What are the difficulties with tuning carbs with this set up?

BUMP. Can anyone answer my question please?
Cheers
Don

[tkent02]

I would say try it and become the resident expert.

[p_s]

Do you need height as well as balance? Could you please explain? What are the difficulties with tuning carbs with this set up?

My understanding (and I've never balanced a bank of carbs) is that some bikes require you to set the vacuum to a certain level on each carb and some require that some carbs have a certain amount more or less vacuum than other carbs and most bikes just require that the vacuum levels are all the same (and that it doesn't matter how much vacuum there is). If you just need all the vacuum levels to be the same then any number of improvised manometers should just work. Otherwise you need numerical measurements and calibration.

Same way we can both race our bikes at the same time and tell whose is faster, but if we race one at a time we need a stopwatch.

[Suzuki_Don]

OK. Thanks guys quick response.

[Kcwiro]

This looks interesting I think I will take it one step further with my buddy... I am going to try and use jars of ATF and the method described in that other thread. Principals sound the same...ATF not gong to mess up anything inside the engine if it somehow does get ingested correct?

[PAULYBOY]

Hey! Howzabout using good old gasoline?