Throttle body sync procedure discrepancy in manual

[WetDuc]

My service manual for my 07S2R1000 states to sync throttle bodies by adjusting the air bleed screw on the cylinder with the lowest pressure to equalize both cylinder pressures.  OK, fine. 
Other sources online state to sync using the butterfly adjustment screw between the two throttle bodies.   
Which method is correct?!

[brad black]

>>sync using the butterfly adjustment screw between the two throttle bodies

do that first with the air bleeds wound fully in, checked at varying rpm.

>>sync throttle bodies by adjusting the air bleed screw on the cylinder with the lowest pressure to equalize both cylinder pressures.

do that second, altho on an open loop bike you adjust them to give the same idle mixture, not vacuum.

[WetDuc]

Brad, trust ME...I trust YOUR input fully, but it's weird the duc.nu manual does not outline the whole procedure that includes the sync screw between the TB's. 
I'm going to hook my bike up to the manometer today and I'll report back.  I appreciate the response, just wanted to ask that question before I did the physical test.   
Thanks!

[WetDuc]

So I tried a TB sync this morning.  First measurement showed they were waaaay off at idle. 
Closed air bleeds and adjusted the TB sync screw to get the manometer reading equilibrated as best I could at 1200 and 4000 rpm.   They are slightly different vaccuum at each setting, but from what I've read online this may be OK.
Bike idles around 1200rpm with both air bleeds totally closed.  It still hunts on hot restarts, but it seems like less (maybe hunts 1/2 the restarts instead of every single time like it was before the sync). 
So it does seem better, but not quite perfect yet.   Test ride was very smooth in low rpm after the sync. 
Trimmer set to 24 and air bleeds closed right now (07 S2R1000 open airbox, full exhaust,DPECU). 
I'll be adjusting my valves this winter and want to tune after that so right now is sorta just practice runs and checks. 
I don't have access to a gas sniffer yet, but I'm still looking.

[ducpainter]

are your air bleeds still closed?

[WetDuc]

Yes, I did the test ride with both closed.   I noticed it idled a bit lower than normal like that which makes sense...I think. 

[ducpainter]

I'm sure someone will correct me if I'm wrong, but I believe the rest of the procedure calls for opening the bleeds 1/4 turn.

Then rebalance by turning the screws slightly to get even manometer readings

[WetDuc]

I can definitely try 1/4 out each.  It IS saturday.
I'm guessing the procedure differs because there is one way to do it for a closed loop bike and a different way an open loop setup.

[ducpainter]

I can definitely try 1/4 out each.  It IS saturday.
I'm guessing the procedure differs because there is one way to do it for a closed loop bike and a different way an open loop setup.

I'm going by the procedure for a 750 SS.

I leave my FI stuff to my tech because he has the tools to do it.

[brad black]

on bikes with idle control the air bleeds will not affect the speed unless they're out far enough that the system can't lower it with the valve fully shut.

most of the closed loop bikes come with them both fully in.

i've found over the years that having them fully in on open loop bikes can lead to a very dirty mixture - lots of hc and o2.  wind them out 1/4 turn or so and they clean up to normal levels.  no idea why.  happens on both 2v and 4v.

if it's open loop then you should be setting the idle mixture on each cylinder individually, first setting the trimmer so both cylinders are as right-ish as you can get with the air bleeds set to give the desired idle speed and equal vacuum, then adjusting each airbleed to give the desired mixture.  on an idle controlled bike i'd probably have one airbleed fully closed and one wound out to lean that cylinder as required.

24 sounds very rich too.  i think the last few s2r1000 i've done have been around 10 - 14.

[WetDuc]

Interesting advice....
So for an open loop bike, adjusting the mix screw of only the one cylinder with most vacuum so it matches the other with respect to mixture and vacuum  does have validity. 
I've got to get my hands on a sniffer.   If I fail to finally find someone who already has one, I'll be putting in an order for a Gunson unit today. 
I do want to be able to tune FI systems myself, I expect a learning curve and realize I need all the tools to do it right so a gas tester is, I think, the only final tool I need (I have VDSTS and all other basic tools).
I was thinking of trying with the trimmer set about 10 points lower to see what it's like. 

[brad black]

you don't worry about vacuum, only mixture.  wind out the air bleed of the richer cylinder.

[WetDuc]

OK, I gotcha.  


So, in the case of my bike and the mods it has, it seems this would get-r-done, please correct me if this is wrong:
1. Both air bleeds closed, set trimmer to a value around 10-14, equalize vacuum using the snyc screw, reset TPS.
2. Adjust mixture by opening air bleed of richer cylinder.  
3. Reset TPS.  Go fast.

Ya?

>>>edited

[brad black]

no

1/ wind out idle stop on rh throttle body so that it doesn't touch anything or have any effect.
2/ reset tps
3/ wind in airbleeds
4/ start and warm up
5/ set balance for best compromise at varying rpm using the sync screw
6/ check idle mixture
7/ adjust idle trimmer to get the leaner cylinder to the desired setting
8/ wind out airbleed of richer cylinder to lean it off to the same setting as the other cylinder
9/ recheck mixture of leaner cylinder to see if it has changed
10/ adjust as required
11/ ride in any manner you care to

more info, same throttle bodies, different tps - http://www.bikeboy.org/ducati2vthrottleb.html
some linear tps info - http://www.bikeboy.org/ducatitps.html

[WetDuc]

Dude, thanks a ton for the procedure description!
My Gunson unit is on it's way to me, so soon I should have all the tools I need, finally.

In the past I have perused the links you posted related to my system. 
I know I don't just speak for myself when I say that your efforts to make Ducati information more accessible to normal folks like me does not go unappreciated!

When the Gunson unit arrives I'm going to do a tune before my valve adjustement as a practice run.  I'll dive into the valve joys this winter (may need a tip on that as well when the time comes), and then go through your procedure once more for what hopefully will be the final big tune.