I am trying to sync my carbs, I am using the two bottle method. I started out with 3 and 4 they were even on the mark had to adjust alittle but not much. I then went to 1 and 2. Carb one sucked all the fluid to the one side and started going into the carb. I tried to adjust but could not get it to reverse no matter what I tried. I switched to 2 and 3 and it did the same thing except 3 was now pulling the fluid out of the bottle.

Any advise would be helpfull

Thanks

Ok after some messing around I am able to sync the pairs sepratley. but when i hook up 2 to 3 it goes nuts and 3 sucks all the fluid out of the bottle.. still can't get it adjusted, I looked for cracks and air leaks but didn't find anything that would cause issues.

First, you should not have that much fluid in the bottle, fill one 1" from the top and pour half in the other.

Second, on the 2/3 sync, you're supposed to do that last, because #1 can hold #2 open, which would cause #3 to have more vac, AND SUCK all the fluid out. That's what's happening to you !!

Sync 3/4 then sync 1/2 then sync 2/3

I started with 3/4 went to 1/2 then 2/3 and both sets had even vac just not together. I only have 2 oz in each bottle not even half full. i've been at this for about 2 hours and can't seem to get it right. In fact I've made it worse I should have just left it alone.

At this point the Idle set screw is all the way out and it's idleing at 2k and above so I can't even adjust the idle unless I want to go over 2k. I am using the YICS tool just as a side note.

I need a break. Anyone live near Galion, OH and want to come and help me

both sets had even vac just not together "" ""

Does this mean you got 1/2 and 2/3 to sync up?
Then you're done, but you have a vacuum leak.

If you are REALLY done, as a final test, you can check #1 against #4 on the 2 bottle method, just don't adjust anything. (final test).

""In fact I've made it worse I should have just left it alone""
This is why I like the 4 tube Manometer, you can see exactly what's going on, and adjust any screw in any order. All 4 are telling the tale all the time. If by "worse" means you can't get your idle down, you have more tuning or trouble shooting to do.

How are you adjusting your pilot screws? Did you tighten your intake clamps? What color are your plugs? More info please.

TIMEtoRIDE do you have any pics/drawings of a 4 tube Manometer. i need to build one!!

To start you off

www.xjbikes.com/Forums...rt=45.html

but there's better Manometer threads. I'm thinking of doing one,
" Free Manometer" listing where and how to get all parts for free.
Don't forget the baffles !

There have been times in the not-too-distant past that I have messed with trying to synch for so long that the process is lost. I have had to bite the bullet, pull the carbs (again) and do a bench synch to get those butterflies where they should be.

Well Andrew that's exactly what I ended up doing.. pulled the carbs and wow the butterfly's were all different, to me it's Kind of comical I guess since I spent soooo much time on it and got nowhere, but it's all in the name of Yamaha right?

Anyway Got em back on the bike i'll try again tomorrow and post my results good or bad..

You can't get an accurate measurement of the Manifold Vacuum without fabricating some Vacuum Line Restrictions.

Get some UNIONS and make-up a handful of Restrictors.

Put a Spray-type Red Tube all the way through the Union.
Add some Epoxy to surround and seal the Red Tube within the Union.
Once the Epoxy cures, cut the Red Tube's ends off.

You want to create a NARROW Inside Diameter. Very small.
The Manifold Vacuum pulling on this small diameter will have less strength.
Won't let the Engine suck-up fluid or mercury.
Keeps Needles on Gauges from fluctuating wildly during the readings.
You shouldn't be trying to Sync without using them.

Here's what one looks like.
The Red Tubs is open at both ends:

...of course, there is always a reason why we can't get that synch right first time, be it having wildly fluctuating equipment or a small air leak - the latter being my problem. I couldn't identify that small air leak until I saw a drip from between #3 & 4. Turns out, on reassembly of the carbs I had "pinched" the o-rings on the fuel supply rail between 3 & 4 and was leaking fuel and possibly air. Re-seated those rings, bench synch and behold a great synch first time.

Andrew, when you clean the carbs do you separate the individual carbs? I am having the same problems as reported above, except, any attempt to sync was making things worse. Now I just did it by ear since i dont know if it was the 4 bottle manometer i built out of plastic juice bottles or an airleak or what - I just wanted to ride and not let the best be the enemy of good. I dont know if my carbs are in sync, they run. After riding for sometime, all the cylinders are showing lean and the engine is running hot so I turned the mixture screws out half turn and now have to read plugs. I did buy 4 vacuum gauges from ebay and am thinking of using that for a sync.

I don't understand why some of you are going through all the trouble to build two and four bottle sync tools.
It would seem to me that balancing-out the Carbs using a single Vacuum Gauge would be a whole lot easier than trying to deal with all that plumbing.

I do realize there is that "Visual Factor" of seeing the liquids level in some "Sight-related" arrangement similar to columns of mercury in Carb Sticks.
Sure. It's nice; but unnecessary.

Accurately measured Manifold Vacuum is just as easily adjusted between the Carbs using a single, uncomplicated Vacuum Gauge and recording the values; then making them even.

No oil, water, bottles, frustrations, mess or any interferences that might cause the readings to be inaccurate.

But, if you are having more fun playing with the tubing and bottles; that's OK. I know you are striving for accuracy at this stage of the game.
Just remember:
Even the most talented Tech's were using a single gauge before somebody took four small gauges and ganged them on a rack of plexiglass.

When we are doing the synch, we are striving for the same thing - an even reading for each of the cylinders (carbs), even though we are accomplishing this with different tools of the trade. Single vacuum gauges, multiple gauges, electronic etc., but do remember it is vital that other things are seen to before attempting synch'ing.

The valve clearances must be checked and adjusted and the carbs should be as clean as possible, otherwise we are just chasing our tails with whichever synch method we are using.

Engine synchronisation and mixture control go hand in hand (once we are satisfied everything else is in order). Personally, I have done a synch, checked the mixtures using a colourtune and then another synch check.

In order to clean the carbs it is not absolutely necessary to split the rack. I will say however if you are uncertain if the rack has ever been split and the seals replaced it is a good idea to do it. It is definately not that difficult to split the rack and put it back together and there are a couple of guides with pictures on the site here that will help. Spring orientation etc. was my biggest concern but it was easy with the guides. Just take the time to do it properly and don't pinch an o-ring when re-assembling like I did otherwise it will have to come back apart!

Thanks ricko, I was getting ready to build one more tool, then i read your post. I have been using my dads 40 year old vacum gauge with a mig tip inserted in the line and a 1/4" fuel filer and some masking tape and marker. It worked on hundreds of race cars!!