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Old Jul 19, 2011 | 09:30 AM
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Default throttle body sync

Ok let me start by saying most think of this with more than 1 carb and it's amazing how many people yes motorcycle mechanics I have spoken to over the years who think its not possible or necessary on EFI.
I use to do it as regular maintenance on my fjr1300 and on my gsxr 1000 and let me tell you the different is night and day.
If they are out of sync the cylinders feel rough and like they are fighting each other. Get the EFI synchronized and it really smooths out the engine.

My fjr and gsxr have little nipple's that your http://www.carbtune.com/ go on and then small screws on the throttle body that each one get adjusted by.
Usually you will increase the running idle to a higher rpm and I think for the fjr you would sync to cylinder 3.

Anyway, my long drawn out story is to ask if anyone has ever done this on a Harley EFI?
I have been told that Harley uses a sensor to detect the pressure and is adjusted electronically and there are no screws to do this with.
Is this true?
 
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Old Jul 20, 2011 | 09:52 AM
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Wow, No one knows the answer one way or another?
 
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Old Jul 20, 2011 | 10:11 AM
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there is only one throttle butterfly on all harley efi (except marelli, but that doesn't coujnt!) there is no possible syncronizing on harley fuel injuection
 
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Old Jul 20, 2011 | 10:18 AM
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the map sensor (manifold absolute pressure) reads amound of vacuum for ecu to know amound of demand on moror along with throttle switch ( lets ecu know angle of throttle plate) so it can determine amount of time (milliseconds) to keep injectors open, your bikes had multiple throttle plates each one having its own idle speed screw, that needs to be equal on all cyls in order for everything to begin at the same time, basicly apples and oranges here
 
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Old Jul 20, 2011 | 10:24 AM
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Originally Posted by harleycharlie1992
there is only one throttle butterfly on all harley efi (except marelli, but that doesn't coujnt!) there is no possible syncronizing on harley fuel injuection
Duh, Now damn I feel stupid.
Thanks for pointing out the obvious LOL!
 
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