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Discussion Starter · #1 ·
throttles have adjustment screws, why the manufacturer does not provide synchronization ???

did anyone check the vacuum in their motorcycle? ?

vacuums are identical or different? if different, by what value?
 

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It would be a great surprise if the bike would need manual throttle body synchronisation as a standard maintenance procedure. This happens automatically.
 

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Discussion Starter · #3 ·
CRF has no autoregulation device in the injection system
only the engine speed is autoregulated by the engine controller
 

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The throttle body is made with the left and right throttle blades on a common shaft like an automotive 2-barrel carburetor. No way to get out of sync. EFI systems have a baseline idle blade setting, then the ECU does the rest with the IAC valve. I couldn't find any mention of an initial setting procedure in the FSM, so they don't want anyone turning a "what's-this-do?" screw.
 

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Discussion Starter · #5 ·
The throttle body is made with the left and right throttle blades on a common shaft like an automotive 2-barrel carburetor. No way to get out of sync. EFI systems have a baseline idle blade setting, then the ECU does the rest with the IAC valve. I couldn't find any mention of an initial setting procedure in the FSM, so they don't want anyone turning a "what's-this-do?" screw.
crf has two bypass screws on the front of the throttle body
 

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mdxmd you seem to know all the details so why ask the question then post critic replies to keep the thread going? Seems you are itching to tell the whole story about your hypothesis so go ahead and post it.
 

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Discussion Starter · #7 ·
mdxmd you seem to know all the details so why ask the question then post critic replies to keep the thread going? Seems you are itching to tell the whole story about your hypothesis so go ahead and post it.
I am looking for any information on this subject. If there are adjustment bolts, there should be information about the adjustment itself.

CRF1000 :

two cylinders
two throttles
two injectors
two adjustment screws (air bypass)

why there is no auto synchronization TB

one lambda probe
one common Map sensor
one common stepper motor for regulating idle speed without separate air volume control for each cylinder

I checked the vacuum in my motorcycle and the right cylinder was about 10mmHg higher than the left one.

99% of motorcycles, vacums should be equal. There are a few exceptions, e.g. HONDA VTR1000 where the vacuum difference is 10mmHg. So I ask myself the obvious question about CRF.
 

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I think a lot of people see problems where there is no problem. And of course the reverse is true, until parts fall off. I, like many people, have the 16-17 FSM. There is not one word in there that I could find about adjusting the throttle body, or even about checking vacuum... And so there is no need to do so.
Any "adjustment" screws are certainly there so the unit could be set and calibrated on initial assembly, and any change to those screws would certainly throw off the baseline and it would never run correctly again. All of the balancing and adjusting is done on the fly by the ECU, guided by the raft of sensors.
 

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Discussion Starter · #9 ·
All of the balancing and adjusting is done on the fly by the ECU, guided by the raft of sensors.

the sensors are used to read the parameters but are not used for adjustment, the ecu controller in CRF can only change the engine speed, fuel ratio and ignition angle. ECU cannot balance vacum pressure....
 

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My 2016 DCT has had an issue for about a year where it dies randomly. After a very long fight, they finally tore it down and found uneven vacuum between the throttle bodies. Then tested against another bike and it was not this way. The dealer replaced both throttle bodies w/ injectors, plugs, wires, header. The header was very blue on just the right bank. The paperwork says that one side had 180psi and operated at 280 degrees. The other was 190psi and operated at 360 degrees. Not exactly sure what that means, maybe you could tell me?
 

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I don't understand what the relationship is between the pressure unit and the angle?
the sensors are used to read the parameters but are not used for adjustment, the ecu controller in CRF can only change the engine speed, fuel ratio and ignition angle. ECU cannot balance vacum pressure....
Having the same problem with the new cb1000r. there is no service shedule for fuel injection sync, all other manufacturers have one but not honda for this bike. what magic is honda doing, or do you have to scrap your bike after 50k. the service schedule on a yamaha mt 09 is every 6k for a sync, what is honda doing that removes this need for all other bikes have regular syncs..??!!!!
 

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Having the same problem with the new cb1000r. there is no service shedule for fuel injection sync, all other manufacturers have one but not honda for this bike. what magic is honda doing, or do you have to scrap your bike after 50k. the service schedule on a yamaha mt 09 is every 6k for a sync, what is honda doing that removes this need for all other bikes have regular syncs..??!!!!
Maybe Honda has figured that out. There is tremendous opportunity to do some really cool voodoo in modern embedded firmware.
 
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