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Throttle Synchronization?

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I remember the first syn tool I built back in about 70 for trying to keep the 4 cyl honda kinds sorta together with it's 4 throttle cable junction. The Store that I did business with let me have all 7 gauges it had for that application. I had a vacuum gauge on my car back then , so, just went outside and plugged each one into the line. Kept the 4 that read the closest together. Some were as much as 1.5 lbs different. Later got a Murcury Manometer. it was so nice back then , In fact still have that dude on the shelf but needing new tubes for it. May have to revive it next syn on the bandit.
 
This is probably a stupid question, but why do fuel-injected bikes need throttle synchronization? Fuel-injected cars don't.
 
randian said:
This is probably a stupid question, but why do fuel-injected bikes need throttle synchronization? Fuel-injected cars don't.
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Most fuel injected motorcycles have more than one cylinder, and if the do they usually have more than one throttle body and require the throttle bodies to be synced to each other.

Now most fuel injected car engines only have one throttle body, and obviously need no syncing, but I would think that if you had an engine in your vehicle with multiple throttle bodies, then you would also need to sync the throttle bodies to each other just like on a motorcycle. :rider:
 
MetrickMetal said:
Most fuel injected motorcycles have more than one cylinder, and if the do they usually have more than one throttle body and require the throttle bodies to be synced to each other.
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Why isn't it done in software? One master, N slaves, automatic sync. You have sensors on every throttle body, right?

For that matter, with modern bikes using the "tank" as an airbox (rather like cars do) why not go with one throttle like a car does? Is there really a need to emulate carburetors?
 
The closer to the intake valve you inject the fuel the more precisely you can meter it. More importantly, by timing the fuel pulse to the opening of the intake valve, the better you can control the mixture, which lets you get more power without more emissions.

The typical mass produced car uses one throttle body because it's cheaper. More performance oriented cars are more likely to have individual throttle bodies. But as getting more performance out of less fuel becomes more and more critical in cars, you're starting to see more cars with individual ones. In fact, we're starting to see more cars with direct injection, where fuel is injected at high pressure directly into the cylinder, after the intake valve closes and immediately before the plug fires.

As for syncing in software, that won't work because syncing isn't adjusting the fuel, it's adjusting the air. More accurately, you're syncing the butterflies in each throttle body, to ensure they open at precisely the same time.
 
BlueStreak said:
As for syncing in software, that won't work because syncing isn't adjusting the fuel, it's adjusting the air. More accurately, you're syncing the butterflies in each throttle body, to ensure they open at precisely the same time.
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I understand, for mechanical throttle bodies. The trend is for new bikes to have drive-by-wire throttles with electrically actuated butterflies, as has become nearly universal on cars. Don't they require syncing too? If so I find that odd, they should all be slaved to the same master control signal being generated by the electronic throttle module.
 
say you did a sync..Then later on remove the secondary flies...Would that necessitate another sync ?
 
On syncs , you're controlling the position of the manual throttle valve which feds air to the cylinder or cylinders. If you change a resistance factor to the air , like removing the secondary, computer controlled valves, yes , you would be wise to re sync your throttle bodies. I have run across some engines that you can adjust each injector to balance the cylinders. But, only in commercial applications. Like large compressor engines and the old Fairbanks Morse Sub engines where you had a crankshaft on top and the bottom, bringing the pistons together in the middle to form the combustion chamber. You want to talk nightmares in sync jobs. Try those dude. I had 3 of them years back when I worked for Shell offshore I was responsible for maintenance on.
In thinking about the new Fly by Wire stuff. And not really ever studying or having to work on them. Perhaps the throttle positioning screw would have to be used unless there would be a software program developed for this feat.
Even though I don't do any mechanical work, being totally retired, cept on my own stuff, if I can. And, only do what I have to do to keep it running down the road. ;-) I still like to keep up with the modern stuff and mechanic of same. I'll leave the application phase to you younger , more energetic people.
 
randian said:
I understand, for mechanical throttle bodies. The trend is for new bikes to have drive-by-wire throttles with electrically actuated butterflies, as has become nearly universal on cars. Don't they require syncing too? If so I find that odd, they should all be slaved to the same master control signal being generated by the electronic throttle module.
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There's still a mechanical connection between the electrical actuators and the butterflies. In theory, I suppose, the factory should sync them perfectly when assembling them, and lock them in place so they never move. In reality....
 
BlueStreak said:
There's still a mechanical connection between the electrical actuators and the butterflies. In theory, I suppose, the factory should sync them perfectly when assembling them, and lock them in place so they never move. In reality....
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Unless that mechanical connection is broken or failing, it shouldn't matter. The actuator should have sensors telling it the position of the butterfly so that it can keep its position in sync with the master control signal. This is commonly called a "feedback loop". Synchrony follows as a matter of course absent mechanical or sensor failure. Perfect physical synchrony is impossible, but skew between the throttle bodies should be on the order of fractions of a millisecond in advance or lag. Should be good enough, unless there's something about a motorcycle's operating environment that makes it impossible.
 
randian said:
Unless that mechanical connection is broken or failing, it shouldn't matter. The actuator should have sensors telling it the position of the butterfly so that it can keep its position in sync with the master control signal. This is commonly called a "feedback loop". Synchrony follows as a matter of course absent mechanical or sensor failure. Perfect physical synchrony is impossible, but skew between the throttle bodies should be on the order of fractions of a millisecond in advance or lag. Should be good enough, unless there's something about a motorcycle's operating environment that makes it impossible.
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I'm curious, are you trying to talk yourself into performing a throttle body sync, or talk yourself out of doing one. :-P :rider:
 
Rangerscott said:
There's not model # on the gauges?
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Sorry, I thought I had replied back to your question.

There is no model number on the gauges, and when I received them there was a model number on the box, and I think there might have been a sticker on the gauges that had a model number on them, but there both long gone. :doh:
 
Hi Roy, i saw i your previous post about the throttle sync, that the drag of butterflys must be .001. My questions are:
From where you take this information(i mean are you sure about this)?
And .001 is in inch or mm?

p.s.I wrote here because your inbox quota is full.
p.s.2 Sorry for my english

Best Regards

Nikolay
 
I don't think Roy frequents this forum anymore. I purchased his bandit 5 or more years ago. Needless to say the throttle bodies were in perfect sync!
 
superj said:
I don't think Roy frequents this forum anymore. I purchased his bandit 5 or more years ago. Needless to say the throttle bodies were in perfect sync!
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I saw that. I was just reading this thread to educate myself on the TPS. I then checked to see if some of those guys were still active here. It seems most haven't been in 6 years or so...:( Not that theres anything wrong with my bike. I just happened to stumble on this and see that most recommend checking the TPS for -C00 b4 doing the throttle body synchronization. And then this opened a 13 page can of worms that the shop manuals don't even seem to touch on. And if you mess with that TPS screw and the idle doesn't return to normal.....Then it looks like an expensive purchase to have the ISL relearn itself. Of course someone even tried that and still couldn't get it to come down. Not to mention the headache of getting to that screw.

I get exceptional gas mileage of like 47mpg or so. So I'm assuming I'm probably ok. I do have some slight surging at around 2800 rpm's and some snatchiness of throttle when in the upper gears and the throttle is barely cracked. Other than that the bike runs great. That being said, I've had surging and some snatchiness in most my bikes at some point in the rpm range. It also has less vibration than almost any bike I've ever owned. Another thing I noticed, is that I'm assuming these people with the really bad mileage, vibration, and surging, were on 07's, the first year. I wonder if anything was corrected in the fueling system in 9 years.
 
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You're right 1stSuzuki, 47mpg is exceptional, it might even be a record. I always got consistent 40-41 mpg on low test, and 43 mpg on super. Couldn't coax any more than that out of a gallon if I tried.
Back to throttle sync. To anyone contemplating this job (which I never did), proceed with extreme caution. Based on everything I have read on the subject on this site, the odds of making things worse are high, and then finding someone with the knowledge to undo the mess are low. Dealers don't seem to have a clue either.
 
superj said:
You're right 1stSuzuki, 47mpg is exceptional, it might even be a record. I always got consistent 40-41 mpg on low test, and 43 mpg on super. Couldn't coax any more than that out of a gallon if I tried.
Back to throttle sync. To anyone contemplating this job (which I never did), proceed with extreme caution. Based on everything I have read on the subject on this site, the odds of making things worse are high, and then finding someone with the knowledge to undo the mess are low. Dealers don't seem to have a clue either.
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I fill up on 89 ethanol free and always add 2oz. of marvel mystery oil. Not sure if any of that makes a difference. The other day I got 205 miles on a tank and filled with 4.3 gallons. I was trying to see when the last bar and the gas symbol both flash. I chickened out and filled.
 
Ethanol free is getting hard to find around here, also at least 60c more. I don't bother. They say it could account for up to 10% gas mileage penalty so that would put us closer together, also I had a dale walker stage 2 installed, although that didn't seem to change my mileage much.
I say had, because I traded the bandit in for a blackbird 6 months ago. The riding position gave me lower back muscle pain after 2 hours in the saddle. After 5 years I gave up. The blackbird has totally different ergonomics, and works for me.
 
It only took two hours but I've read this entire thread.
'09 1250 here.

I performed the TPS reset procedure, although admittedly I did it the hard way without fully removing the airbox. I'm stubborn that way; hence it only took me an hour and a half to turn that set screw in about 1 1/2 turns to achieve -C00.

I am awaiting Holeshot's delivery of the PAIR removal kit before I fire the bike back up. No sense pulling it all apart twice.

I have a VERY old set of Carbtune Mercury type synch guages in the shop; I hope they'll suffice!

I guess while it's open I may as well purchase new spark plugs, I'm at 17K miles and there is no telling if / when they've been done.

I have the 1200cc K&N air filter installed, I've gutted the catalytic converter and have a 2 Bros Black series can and mid pipe on.

I have installed the new budget Power Commander FC module and so far it suits my needs. After the TB synch I'll be sure to reset the throttle position to 0 in the FC controller.

Cheers to all who've come before me, thanks for all the hard work!!!
 
I'll be syncing mine in the next month or so as I reassemble. Mine runs a bit choppy as it stands, and I can tell from previous experience that this thing needs a sync. I'm fully confident it'll smooth up with a sync.
 
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