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Discussion Starter #1
That is, can the TB's be re-synced via an adjustment screw or similar?

It's evident from my PCV autotune fuel map that one cylinder is sucking more air than the other - and that the difference cannot be completely attributed to preferential cooling on the front cylinder (it seems too big of a difference to me).

Thanks cheers
 

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Do your exhaust pipes have EXACTLY equal length head pipes and EXACTLY the same bends? Do you think both cylinder heads flow at EXACTLY the same rate & velocity at a given throttle position?

This is why the PC has a "trim" function to tune the cylinders individually. All things are not equal. It's not the sync of the throttle bodies.
 

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Discussion Starter #3
See the problem I have with that argument is that its both easy to dismiss the cause of disparities between cylinders, and hard to assign root cause. You're right, there can be many causes for differing fuel maps on each cyl. There can even be differing causes for vacuum disparities between the cylinders at idle. But does that mean it's inadvisable to shoot for matched vacuum at idle? I mean, if the differences in air flow are negligible, so be it. But I'm measuring what suggests a nontrivial difference so I'd like to eliminate that variable (and get the most power out of my engine).
 

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Even when you sync carbs, you don't do it at idle... Most manuals call for 1250+ rpm. No matter what rpm you sync the throttle bodies, they will only be equal at that rpm... it will not insure they are equal across the board.

Do we tune for idle? How much time do we spend idling?
 

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Discussion Starter #5
On my ducati, you would sync at both idle and at just slightly off (in fact, I think it was 1250 or 1500). There were two separate adjustments that would do the bypass air (for idle- called "bleeds") and the relative positions of the TB plate angles - for all other throttle conditions.

I did the sync on that bike and it ran like a champ after. MacGuyvered it with a home made liquid barometer using ATF fluid...

No, they won't always be equal... I'm not striving for perfection here though. I think that my TB's are way off...
 

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I did the sync on that bike and it ran like a champ after. MacGuyvered it with a home made liquid barometer using ATF fluid...

No, they won't always be equal... I'm not striving for perfection here though. I think that my TB's are way off...
I have a Margan CarbTune (2-column system) for syncing.
http://www.carbtune.com

Haven't used it on this bike.
 

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Discussion Starter #7
I like that product line- looks good!

So, does anyone have an answer to the original question?
 

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You CAN sync them. On the '08 and later closed loop bikes, I believe Victory suggests that you don't adjust them. Maybe a sevice manual will be helpful.
 

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Discussion Starter #9
Thanks. Yeah, I will be buying one soon. Not having a garage anymore the work I can do is limited, but I'm probably going to dig into this soon.
 
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