Carb Sync problems

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

http://www.xjbikes.com/Forums/viewtopic ... 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!!

 

well the two bottle method just isn't working for me. I pulled the carbs off last night and followed the instructions on a proper bench sync. reinstalled and tried to start.. No go - finally I got it to start but it jumped up to 5k and kept climing. I adjusted the idle screw and brought it back down to the proper RPM.

Is that suppose to happen after a bench sync? anyway I tried to sync again and once more failed to get 2/3 to sync together. I'm going to bench sync again and try Ricks method for syncing.

I don't have an air leak i've checked all the boots.

 

It depends on what you used. Rick uses a business card which gives a very slight opening. If you use something thicker you will be more open and therefore higher Idle but as you discovered you can use the idle adjust. Same effect.

 

Yeah I used the Business card method, I guess it's just going to be trial and error untill I become a better mechanic on my bike. Or I cave and have someone else do it for me.

Everything worked great before I messed with it, but I really wanted to get the feel for taking the cabs off and cleaning them. Maybe I should have waited for winter

 

Make it easy on yourself!

Gets some vacuum hose from a hardware store.
Unions.
Steal a handful of Golf Tees from somebodies car trunk.

Snip 4 -- 2-Inch sections.
Stick the 2-Inch sections on the Manifolds.
Make "Restrictors" ... Plug them in.
Then, run 4 Hoses to the Left side of the Bike.

Stick a Phillips Screwdriver through a piece of Cardboard and push the 4 Hoses in through the Cardboard.
Mark them 1 ~ 4
Smear some Vaseline on the Golf Tees and Plug the Hoses.

Now, if you are "Real clever" ... you should be able to perfect this move.

Bite the Number-3 Tee and yank it out of the hose.
Put your Thumb over the OPEN Hose and prevent a big AIR LEAK
(It's a quick move)

Move your thumb and plug-in the Vacuum Gauge!
(This is also done quite fast!)

Read it! Get the Value of Number-3.
Mark 3!
We're almost done!

Pull the Guage Line
Thumb the hose.
Golf Tee it shut.
Yank the Tee in 4
Thumb-it.
Put in the Gauge,
Read it.
Adjust it to Match-3

Do the moves.
Move the Gauge Line to 2
Mark-2
Move gauge to Line to 1
Read it.
Match 1 to the Reading on 2
Do the moves.
Read-2
Match 2 to 3.

Done.
Stick-on an arrow of tape or MARK the Guage with a CHINA Marker.

 

With all due respect to the RickCoMatic "Old School" method,

I like the improvement that uses a 4 gang air valve from an aquarium.
It also means you only need to make 1 restrictor/baffle thing.

4 tubes to the air valve,
1 tube to the restrictor,
1 tube to the gauge.

 

I'd say spending the $4.29 for a Rack of Aquarium Valves ... all set-up to do the "Switching" would be the way to go.



Given everything there is to know about how easy it would be to do the switching using the Fish Tank Air Valves ...
You'll save time
And you'll be able to do comparisons with ease.

This gets my vote.
I know what I'll be adding too my toolbox before Friday.
No more worrying about Mercury spills.
The Carb Sticks stay home.

Thanks for the tip.
I'm sold and I don't even have the set-up yet!

 

I'm in for one ;-P

 

Great Tips guys, i'll be off to the pet shop on my lunch break tomorrow. w00t

 

I have a two bottle setup and it is DEAD on.

I let it sit steady for ~a minute before I call it a solid even sync.

If it moves a HAIR over that period, I tweak and wait again.

 

Success!!! I finished my carbs last week and got to color tune and sync yesterday. Color tune went well, The sync went awesome. i used the vac gauge with a restrictor and fuel filter to smooth it out. It took 10-15 minutes and i had to go back and forth several times. i was having a big proplem between 2-3. I bench sync'd but it seemed like 2-3 was way off after 3-4?? I got it real close, it was on either side of a marker line!!!
But the best part was the ride, It pulls alot harder than before and (after new jets) the plugs are tan, not white!!!!

 

OK guys question on the 4 valve setup. I'm using a single valve and it works great. But with this setup I can only see you have to open each valve, one at a time to test each cylinder correct?

The problem I see is adjusting the valve on my setup I can get different readings based on my valve settings. So as you open each valve - even if you go until just before you get fluctuation, how do you know you have an apples to apples comparison? I could see getting different readings each time you opened the valve with no adjustment. Unless you only used the valves for on/off and opened them fully. I use my single valve to get zero needle wiggle.

 

Tman did the liquid level itself in the bottles or did you have to level it with the vacume and then adjust so it didn't exchange between the bottles? The reason I ask is, isn't that the same as just keeping ANY level in the bottles as long as they don't move/exchange?

 

i used the vac gauge with a restrictor and fuel filter to smooth it out. no bottle here.