Throttle body synch

[Reddevil76]

This is something that is done once in a while and I'm not about to invest in a Carbtune just for an infrequent job.

I remember someone once posted something about a homemade thing, using a clear hose, shaped into a U-shape and filled with oil, and using that as a manometer.

Can that someone please provide more info?
How much oil to put in the tube?

Is it very far off in accuracy? I don't mind just achieving 80% accuracy for the cost savings. Anything less, I'd rather invest in a proper tool or send it to the shop.

[Steve TLS]

If you build it properly i.e same tube heights and fill it with exaclty the same amount of oil per tube it will be 100% accurate.

I remember the thread too, I think he used ATF fluid.

[Reddevil76]

Originally posted by Steve TLS
If you build it properly i.e same tube heights and fill it with exaclty the same amount of oil per tube it will be 100% accurate.

I remember the thread too, I think he used ATF fluid.

Since it is a U shape, and essentially built out of one single tube, I assume by saying "same amount of oil per tube" you actually mean ensuring the device is placed level such that the levels of oil on both ends are equal?

I'm thinking of using engine oil.

[Flood]

Go HERE for directions on building one. Or even go HERE

[Reddevil76]

Originally posted by Flood
Go HERE for directions on building one. Or even go HERE

Thanks!

[Steve TLS]

I was thinking of two seperate tubes, not one U shape one.

[Noizemaker]

That was me who posted about my "Ghetto Sync" tool.

Works a treat and cost nothing since I had been tripping over the parts in my garage for some time. Very simply, it is just a piece of hose stapled to a board with a bit of ATF in it. I also had some small air jets lying around that I stuffed in the hose ends near the TB vacuum ports to try to smooth out the air flow, but I am not sure that is needed. I used ATF because it is fairly viscous, easy to see, and it was the only thing on my garage shelf . I used a fairly small diameter hose (about 1/8" ID) for a similar reason, but also I wanted to use a very small amount of fluid to make sure I would not hydolock the bike if it swallowed it. I have seen other people make them with all kinds of graduation marks on the tubes but that kind of seems like they are missing the physics of it to me. What you are doing is syncronizing the TB's, not setting them to some specific value so don't waste your time making it any more complicated than it needs to be! When the bike is running, the goo in the tube will start drifting in one direction, simply twiddle the TB adjusters until the goo stops drifting one way or the other. It does not matter whether the level is the same on each side of the guage, just that it isn't being pulled in one direction by the stronger vacuum of an out of sync TB. It sounds more complicated than it is! Just beware, if they are really out of sync it could draw the fluid into the engine, but in my experience it creeps slowly enough that you have time to shut down or beat it with an axe handle or whatever.

Let me know if you need a better description. I figure you may as well try soemthing like this for a few bucks in parts and if it does not work for you then buy the expensive stuff. Besides, I think this could potentially be more accurate!

[Noizemaker]

Forgot to add the piccy!

[Fabri-Tech]

If done the way the "real" ones are, it does matter if they are the same level. There is usually 1 tube for each TB or carb. There are also usually gradations on the tubes as well. When the bike is idling (Don't rev it, or it will suck the liquid right out of the tubes and into the intakes!) the amount of vacuum being created will affect the level in the tubes. If the TB's/carbs are in synch, they will be "creating" the same amount of vacuum, and the levels will be the same. If they are not the same, adjust the one TB that has the adjustment until they are equal. On an I4, one carb is usually "static", ie, unadjustable. The other 3 have adjustment screws and need to be adjusted to the static one. I assume our twins are this way as well. We also usually made sure the bike was warmed up, and bumped the idle up a few hundred rpms.
Good luck!

[Noizemaker]

I agree that the real ones are graduated and that there is a seperate tube for each cylinder. The problem is that if you were going to build it that way you would need an enormous length of hose to create enough weight in the fluid to prevent sucking it into the engine, or you would need something like mercury for it's density. You also introduce the possibility of variations between the gauges leading to innacuracy. All we need to do is sync 2 cylinders, so the actual readings on a pro unit are irrelevant as long as they are equal. It would be different if we were aiming for a specific value, like on my old FZ750 where you wanted something like 200mm Hg of vacuum. Also, you can rev the engine to check sync above idle without slurping up all the juice like a merc stick can since the TB's are pulling on each other and not just the weight of the sync juice!

[Reddevil76]

Originally posted by Noizemaker
That was me who posted about my "Ghetto Sync" tool.

Works a treat and cost nothing since I had been tripping over the parts in my garage for some time. Very simply, it is just a piece of hose stapled to a board with a bit of ATF in it. I also had some small air jets lying around that I stuffed in the hose ends near the TB vacuum ports to try to smooth out the air flow, but I am not sure that is needed. I used ATF because it is fairly viscous, easy to see, and it was the only thing on my garage shelf . I used a fairly small diameter hose (about 1/8" ID) for a similar reason, but also I wanted to use a very small amount of fluid to make sure I would not hydolock the bike if it swallowed it. I have seen other people make them with all kinds of graduation marks on the tubes but that kind of seems like they are missing the physics of it to me. What you are doing is syncronizing the TB's, not setting them to some specific value so don't waste your time making it any more complicated than it needs to be! When the bike is running, the goo in the tube will start drifting in one direction, simply twiddle the TB adjusters until the goo stops drifting one way or the other. It does not matter whether the level is the same on each side of the guage, just that it isn't being pulled in one direction by the stronger vacuum of an out of sync TB. It sounds more complicated than it is! Just beware, if they are really out of sync it could draw the fluid into the engine, but in my experience it creeps slowly enough that you have time to shut down or beat it with an axe handle or whatever.

Let me know if you need a better description. I figure you may as well try soemthing like this for a few bucks in parts and if it does not work for you then buy the expensive stuff. Besides, I think this could potentially be more accurate!

Looks like I shoulda used air jets in the hose ends. The moment I started the bike, the fluid inside the tube went crazy and I quickly shut it off. When everything settled, I realised 3/4 of the fluid was gone from the tube!

Luckily the fluid was fuel injector cleaner.. so i hope it combusted in the combustion chamber with not much harm to the bike.

Any idea why it didn't work?

[OldTLSDoug]

The thing here is simple. You want the throttle body butterfliy valves moving in "synch". To measure this we use a vacuum gauge. The manometer will work if it is big enough for the pressures encountered. Meaning, for example water pressure is about one-half a pound per foot, or 2 feet of water gives about 1 psi. So, depending on the density of the fluid, and I would assume injector cleaner would be les dense than water, if you had a half a pound of difference you might move the column of fluid at least 6 inches or more. So if your gizmo doesn't ahve enough hose, you may be doomed to repeat this until it does.

The vacuum settings need to be equal or you have not synchronized the TB's. If the level in the tube is not equal, then your TB's are not synchronized. The motorcycle engine on the TL was designed to run best with the throttle bodies synched, so it is important to get them equal.

I agonized for a while and just bought the damn Suzuki adjuster, it works perectly as designed and the manual describes it's operation.

[Noizemaker]

Originally posted by Reddevil76
Looks like I shoulda used air jets in the hose ends. The moment I started the bike, the fluid inside the tube went crazy and I quickly shut it off. When everything settled, I realised 3/4 of the fluid was gone from the tube!

Luckily the fluid was fuel injector cleaner.. so i hope it combusted in the combustion chamber with not much harm to the bike.

Any idea why it didn't work?

I guess the density of the cleaner was a bit on the low side. I think fuel injector cleaner is a bit on the watery side isn't it? I used ATF and it moved so slowly that there was plenty of time for me to set down my beer and hit the switch if it started creeping up one side toward a throttle body. Motor oil would work too but I had none handy. The air jets likely lessened the effect as well. A friend of mine used some scraps of shop rag stuffed in the ends of the hose to slow things down, but I would suggest a little bit of dowel or something with a hole in it from the smallest drill bit you have for each hose end.

Good luck!

[Noizemaker]

Originally posted by TLRDoug
[B] The manometer will work if it is big enough for the pressures encountered. Meaning, for example water pressure is about one-half a pound per foot, or 2 feet of water gives about 1 psi. So, depending on the density of the fluid, and I would assume injector cleaner would be les dense than water, if you had a half a pound of difference you might move the column of fluid at least 6 inches or more.

This would be true if there were 2 seperate chambers but there is just one hose that connects between the throttle bodies, so all it is seeing is the relative difference in vacumm, which is quite small. The fluid creeps one way or the other depending on which TB is creating more vacuum, when it isn't creeping anymore then they must be synchronized. The levels in the tubes do not matter in this closed loop system.

Think of it this like a tug of war. Although the forces on either side of the rope are large, the flag moves very little and when it is not moving at all the teams must be pulling equally. If we were trying to measure the strength of one team by tying the rope to a tree with a tension meter, then yes we would need a sturdy tree to resist the force.

Now, if you will excuse me, I think I need to go lay down.

[JiffyPark]

Hey Doug how much was the Suzuki tool?