Synchronize Throttle Bodies

[Kilowatt Kid]

I have a 1999 1100RT and I want to sync the Throttle bodies. Which kind or what brand of synchronizing gauge do most people buy and use? Not looking for the cheapest, looking for a good one with accuracy. Thanks

[NonComp]

If you want cheap AND a good one with accuracy, make your own out of a board, piece of clear tubing, some wire clips and some two stroke oil. Mine looks like this. It works great.

 

[Richard_D]

Morgan Carbtune http://www.carbtune.com

[Starfighter]

I also use a manometer. (tubing on a steel yard stick)

Good results and cheap. ( I use ATF in mone)

[ltljohn]

I use a home made one like the one above. Compared it to a Twin Max during a tech day and it is dead on and only cost me $5 to make.

[tomk99r11]

You have little to lose by trying the cheap to make manometer, takes little time and is indeed cheap. I had one but now use a TwinMax with great results. For my use, it is easy to operate, dials in nicely, and packs away much smaller than the manometer. It is important to remember to change the 9v battery each year though. Good luck with whatever you choose.

[boatzo]

Like Tom, I have used the manometer and it works well. I currently use a Twinmax because my son bought one to use on his GS and it has been stored in my shop. The Twin max can be a little bouncy and the manometer seems smoother.

[Danny caddyshack Noonan]

I use a twin max and this process

TBSD

 

This process is found here where there are several other oilhead tutorials. ADV Wisdom

[philbytx]

+1 For Morgan Carbtune

[NonComp]

The Twin max can be a little bouncy and the manometer seems smoother.

I have a friend who has a Twin max. I borrowed it a couple of times. Same issue, a bit bouncy. So I made the manometer. Now my friend wants to borrow the manometer...

[Danny caddyshack Noonan]

Did I mention you can ride with the TwinMax, on tank(tape) or in/on tankbag, to verify your settings still apply when out of the garage? You can do the same with a manometer but it's hard to hole with your leg.

[Peter Parts]

Did I mention you can ride with the TwinMax, on tank(tape) or in/on tankbag, to verify your settings still apply when out of the garage? You can do the same with a manometer but it's hard to hole with your leg.

 

Smart and funny.

 

I'd only add, riding with dual vacuum gauges hot-melt-glued to a board clamped to bars has ALL the benefits of a TwinMax plus: more accurate, easier to read, and most important, gives absolute vacuum readings as well as the cheapie relative/balance readings of the TwinMax.

 

Ben

 

Footnote: liquid manometers are very precise for balance - far too precise for this kind of tuning; after a day of riding, the precise liquid manometer will tell you that you are out of synch (true, but tiny and trivial but like some medical exams, leads to further wasted testing).

[oldyam]

 

Footnote: liquid manometers are very precise for balance - far too precise for this kind of tuning; after a day of riding, the precise liquid manometer will tell you that you are out of synch (true, but tiny and trivial but like some medical exams, leads to further wasted testing).

 

However following your line of reasoning the tiny drift which by your own admission started off from a more accurate point in the first place, using more precise equipment, should mean that the TB's will be closer to synch after a days riding than by the coarser method using the vacuum gauges.

[ShovelStrokeEd]

Further footnote. I work with vacuum gauges and precision pressure transducers all the time. When you start comparing them for accuracy, vacuum gauges fall far short. They may even be matched initially over some small portion of their range but, given a bit of time and vibration, they invariably drift apart.

 

I'll shock the world and agree with Ben on something though, a water manometer is way too precise a tool, unless you understand that you just don't use the precision. I can get an idling motor to within 1" WC easily and quickly and even, with a bit of fiddling, get one running at 3K RPM to near the same. Now that is really, really precise, on the order of 0.08" Hg. I don't expect it to be able to repeat for any length of time though.

 

If you really want a handy thing for this, Dwyer Instruments sells a thing called a Magnehelic. Differential pressure gauge, can be had in -15 0 +15 inch Hg gauge, requires no power and comes with spigots of the right size. I don't remember what I paid for mine, I've had it for about 15 years now. Can be wall mounted, stuck on a photo tripod, bungeed to a tank. Very useful for load testing balance.

[ShovelStrokeEd]

Yet another footnote and rarely mentioned in any of the instructions for TB balance.

 

Keep a really careful eye on temperature when you are doing this. Ideally, you want either 1 huge fan or 3 small ones blowing on the individual cylinders and the oil cooler. Get the motor hot and you will lose your balance.

[oldyam]

Used to see a lot of the Dwyer magnahelic gauges on boilerhouse walls in the times of balanced draught boilers ( most a bit large for on the tank though ;-)

[notacop]

Boy, youse guys are really getting sensitive with expensive balancing tool. Do it by sound and feel of vibrations It's not too hard to get it by hand. Then get the wife's best crystal and see if a glass of Geverstraminer will rest stable on the tank. Fine tune for least breakage.

[Selden]

The Dwyer magnehelic gauges are interesting, but there seem to be a lot of possibilities. Which one is appropriate for this application?

 

http://www.johnsherman.com/gauges/magnehelic.htm

[philbytx]

I use the Jaguar V12 method myself .

I just stand a 50 pence piece endwise on top of the motor !

[ShovelStrokeEd]

Seldon,

Either the 2300-0 or 2330 will work fine.

 

2 accessories you might consider are the portable kit and the air filter kit.

[AndyS]

Morgan Carbtune http://www.carbtune.com

 

Simple, Effective, ready made, no batteries or calibration required.

 

Andy

[dan cata]

I used to have a twinmax, now I use a hose + oil in it

[Peter Parts]

The Dwyer magnehelic gauges are interesting, but there seem to be a lot of possibilities. Which one is appropriate for this application?

 

http://www.johnsherman.com/gauges/magnehelic.htm

 

If you match best-pair-of-three vacuum gauges, you have all the accuracy you need. As the picture in my write-up shows, mine are still spot-on after 40 years.

 

If you go riding with gauges, you'll need something that will read up to (and won't self-destruct at) maybe "25 inches." I don't know what "inches" are but that is how my vacuum gauges are marked. Might be inches of beer. I get readings around "15 inches" on engine over-run.

 

Umm, lotsa force on the butterflies, eh. Does a TwinMax tell anybody stuff like that? My ATF manometer would fill my cylinders with ATF at those forces if unbalanced - DAMHIK, no kidding.

 

Interesting to eyeball imbalance at over-run. I've never been able to synch my TBs for it, as well as normal under-load butterfly angles. I wonder if it could be done?

 

But if I lost my vacuum gauges, I'd sooner build with solid-state sensors than with trick mechanical gauges, that's for sure.

 

You can make your own TwinMax with a Freescale Semiconductor (formerly known as Motorola) MPX2100DP, about us$10. Haven’t explored inside my TM, but that’s prolly what’s in it.

 

Ben

[Boffin]

Ben, the inches refer to inches of mercury (standard unit) with 29.92 inches (usualy rounded to 30 inches) being 1 atmosphere.

 

As you say, vaccum guages tell you what absolute vaccum you are getting in the throttles but I am not sure what information that data provides? In other words, what is right, what is wrong and if it is wrong what does that tell you that is not available by other means - or, how do you know what to fix?

 

Andy

[ShovelStrokeEd]

Andy,

The vacuum gauges do work, they tell you what the vacuum is, relative to atmosphere, at each individual port. Match the vacuum readings on both gauges and you will be in balance. I prefer the direct method by using a differential meter/gauge/manometer for balance measurement, but either will work.

 

40 years ago, I had a bank of 4 gauges with snubber valves installed for synching the carbs on my CB750. They worked pretty well for awhile but gradually, the gauges would drift out of calibration (different readings when hooked to the same vacuum source) and I quit using them and made my own common reservoir mercury manometer. Even later, I bought a set of carb sticks (same principle).

 

I now use a water manometer, in differential mode, for all my TB synching needs although it is a minor PITA on the Aprilia which requires the rear cylinder to lead the front by a bit. A bit is about 1.2" Hg which translates to 15.6" WC differential.

[Boffin]

Ed, i know that vaccum guages work - I used to use them but ditched them because of innacuracy. What I do not understand is what knowing the actual absolute pressure adds to the story, as opposed to just the differential pressure.

 

I now use a manometer because I am too mean to buy a Mogan Carbtune

 

Andy

[ShovelStrokeEd]

The real vacuum value, within reason, is meaningless in terms of the TB synch. It can/could be a useful diagnostic on a sick running engine.

[Peter Parts]

Here's the ONLY thing a TwinMax tells you: "the tiny needle is half a scale mark high, if I am reading that right; it is to the left and the sensitivity control is about the 60% point, kind of."

 

Here's what dual vacuum gauges tell you (among a lot of other things too): "you are running around 4.3 inches on the left and about 4.1 inches on the right."

 

What the TwinMax tells you is little better "pissing in the dark." But if that is good enough for your purposes and satisfies your meager technical curiosity at the moment, that's fine. Sometimes I use mine for quick driveway checks - handy tool. But if my dual vacuum gauges are in the garage too and the snubbers are in place, they are faster and better in every respect.

 

Ben

 

Footnote: cheap electronic gizmos with 50-cent meters on them are not necessarily more trick than cheap mechanical gauges, just an illusion. If you want a reliable TwinMax-like tool, make your own from the Motorola sensor I mention in my write-up and in previous post. Piece of cake. Cheaper too.

[travelingman]

So to make the manometer you just take a single peace of rubber tubeing an draw in some fluid trans or two stroke . Then make a U shape out of it an connect to the trottle bodies . I've got a older Twin max an a set of carb stix with mercury ' This

sounds it would be great . I have actually strapped the twin

max on the Tank an rode the bike too control the heat better .

[Boffin]

Here's what dual vacuum gauges tell you (among a lot of other things too): "you are running around 4.3 inches on the left and about 4.1 inches on the right."

 

Ben

 

Ok Ben, it gives you those two data points, but what information does that data convey? Do I need to know it in order to tune my bike? If I am running 12 inches on the left and 12.1 on the right instead of the 4.3 and 4.1 what information does that give me other than a greater depression? Yes it is more data, but what can I get from the data?

This is not a dig - I want to learn what these data points could do for me? Is it useful information or just data? Can I get benefit from it? If so, what benefit? Can I justify the cost/effort of buying or building an accurate set of vacuum guages?

 

Andy

[tazplas]

If you are interested in building a manometer then check out this thread.

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=528089&page=1

Should help

 

Cheers

 

Steve

[pokorskij]

Can you elaborate on the recommendation for the portable kit and air filter kit? Thanks in advance.

[Peter Parts]

Here's what dual vacuum gauges tell you (among a lot of other things too): "you are running around 4.3 inches on the left and about 4.1 inches on the right."

 

Ben

 

Ok Ben, it gives you those two data points, but what information does that data convey? Do I need to know it in order to tune my bike? If I am running 12 inches on the left and 12.1 on the right instead of the 4.3 and 4.1 what information does that give me other than a greater depression? Yes it is more data, but what can I get from the data?

This is not a dig - I want to learn what these data points could do for me? Is it useful information or just data? Can I get benefit from it? If so, what benefit? Can I justify the cost/effort of buying or building an accurate set of vacuum guages?

 

Andy

 

Andy -

 

I did say that's data among other things you see as you watch the gauges (with the other eye on the road, of course). A vacuum gauge is like a microscope into the induction tract. Not important to everybody all the time, but some people are curious.

 

To answer your question, there's a big difference between seeing 4.3/4.1 versus seeing 12.3/12.1.

 

If you saw, 12.3, (with a 1.7% imbalance) only anal members of this forum would bother to tune it further. But if you saw 4.3 (a 4.9% imbalance) many normal people would want to get it closer.

 

With a TwinMax, I think the differential reading is the same for both high and low vacuum and in any case you have no idea which ballpark you are in. Well, not exactly the same since the TM scale isn't as fine as a cheap vacuum gauge - see my write-up for the numbers.

 

No way to get much information from a TwinMax.

 

Ben

[tomk99r11]

Ben, a lot of us use the TM with great results so to state it gives no useful information and is like pissing in the dark is ridiculous. Is your adversarial "tone" really necessary?

[NonComp]

For me, the TwinMax is a black box. It might be working. It might not. Is the battery OK? And you would not know unless you compare your results against another instrument -- such as a manometer.

 

A Manometer is exposed for all the world to see. And its simple. When the fluid levels are equal height, that's it. No calibration required. It's cheap. And the worst you can say about it is that it is too accurate...

[philbytx]

I trust that by your statement, you realize that you are defending and supporting THE FRENCH

 

[boatzo]

I trust that by your statement, you realize that you are defending and supporting THE FRENCH

 

 

Well Phil, we also support China in many ways. At least a home made manometer would be made in the USA. (assuming the maker was in the US.)

[ShovelStrokeEd]

Can you elaborate on the recommendation for the portable kit and air filter kit? Thanks in advance.

 

The portable kit gives you a nice box in which to store the instrument and some additional mounting options.

 

The air filter kit gets you the hose and fittings you will need to complete the installation. You won't need the static tubes provided unless you want to also use the instrument to check air flow in your AC ducts at the house.

[Peter Parts]

Ben, a lot of us use the TM with great results so to state it gives no useful information and is like pissing in the dark is ridiculous. Is your adversarial "tone" really necessary?

 

I never said anything like it gives no useful information. It is all you need for a basic tune-up and as I've said in other threads, it even works OK under load (if you have the 9v model) because I've tried it.

 

Did you notice that half a dozen or more times in this thread I mentioned that I use it from time to time, that it is just fine as far as it goes, and that people should consider making their own better one (with a meter costing more than the TW 50-cent unit) using the Motorola sensor?

 

No need to apologize.

 

But all things considered, you are way ahead in accuracy, dollars, and bike diagnostic information using dual vacuum gauges and synching under load.

 

Ben

[ratfink]

And the worst you can say about it is that it is too accurate...

 

Messy, awkward, difficult to store and transport and the liquid can get sucked into your engine. That's the worst I can say about a manometer.

[E30TECH]

I will be doing a TB sync this week and using both, a TM and 2 vacuum gauges. I plan on setting everything up with the TM and verifying with the gauges.

 

I verified the gauges are getting the same reading with a vacuum pump. I was trying to come up with an orifice rather than using the hose clamps as snubbers. I just wasn't sure what size I should make the orifices.

 

I have used a carbtune to sync the TBs on my old M3, which I believe is a better device than the TM. However, the TM is a little easier to use on a bike, especially doing the on road test.

[Peter Parts]

Way to go!

 

The real period of insight is when you go riding (under load).

 

Carry whatever little tools in your pocket for adjusting the Bowden cables.

 

Let us know if you find you are re-setting the cables on the road as compared the setting at idle and tiny-bit-off-idle you started with in the driveway. On a good day, there may be no change.

 

Ben

[Peter Parts]

And the worst you can say about it is that it is too accurate...

 

Messy, awkward, difficult to store and transport and the liquid can get sucked into your engine. That's the worst I can say about a manometer.

 

All true. But there is one thing worse you can say for the people who might still be using mercury: it will poison your nervous system.

Ben

[philbytx]

If you are referring to the Morgan Carbtune, I am confused.

Its a piece of cake to use it on the bike, you can hang it off the windshield by stringing together a couple of bungees .

[E30TECH]

If you are referring to the Morgan Carbtune, I am confused.

Its a piece of cake to use it on the bike, you can hang it off the windshield by stringing together a couple of bungees .

 

Yes thats the one.

 

"However, the TM is a little easier to use on a bike, especially doing the on road test"

 

No need to bungee the TM. I am wondering how I am going to mount the twin vacuum gauges. I am using -4 AN to 1/8" swagelok. From the swage will be a 1" straight piece of 1/8" to connect to the hoses.

 

I was thinking of manifolding the gauges with the TM, but thats too much work.

 

I will post if I found any differences, etc.

[NonComp]

Permanent mounting on the dash would be good. If you put geared adjusters that are cable driven on the throttle cables, you could tune the balance on the fly anytime.

 

My grandfather spoke fondly of the dash mounted spark advance that you change on the fly to adjust for the available fuel grade.

[E30TECH]

I thought about that for a minute. I would use 2 transducers with a digital output. I think the dash would be a little too busy fir that!

 

I could do everything but the adjuster. I'd be lost there

[philbytx]

Forget all that, I'd go straight for the HUD unit in yr helmet

[E30TECH]

If I did that, I would mount the transducers on the helmet

[Peter Parts]

Permanent mounting on the dash would be good. If you put geared adjusters that are cable driven on the throttle cables, you could tune the balance on the fly anytime.

 

My grandfather spoke fondly of the dash mounted spark advance that you change on the fly to adjust for the available fuel grade.

 

That's a one-time one-hand adjuster. The Oilhead ECUs have a surprisingly complex spark map like you wouldn't believe.

 

Ben

 

R1100S has clip-on bars, but here's one idea. Pity you can't see my Maserati gen-u-ine compressor air horns tucked in just under the instrument panel. Pity you can't hear them.