Stock exhaust and the EXUP valve

Hi I was wondering if anyone can help me. I have to install my stock exhaust back on and after hooking everything up I don't think the servo motor cables are doing what they are supposed to do. If I turn my key on, the servo motor turns to the right a little bit, but the actual EXUP valve does not turn at all. I ran the bike and revved it a few times and no movement at all from the EXUP valve. I even put the bike into 1st gear on the center stand and still no response. I read somewhere that the bottom cable to the EXUP valve attaches to the top part of the servo motor and I double checked this to be true. I have experimented by readjusting the bolts holding the cables to the EXUP valve at different lengths of the bolt to see if they tighten or loosen (a few videos I seen I can tell the top valve cable bolt it appears to have more thread then the bottom one and is the only thing I have to go on at this point). At one point I think they were too tight because the motor was making noises but nothing was happening. Can anyone explain why the valve is not moving from turning the key? Does it move when it is idling normally on start up (from videos I am guessing it does) Is there any videos on how to reinstall the servo motor cables? I have ordered a two brothers exhaust but who knows when it will actually show up and I don't want to run without an exhaust obviously so I don't want my bike to sit in the garage waiting for parts. Thanks any help would be appreciated.
 
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It should cycle when the key is turned on after that you won't see any movement as it only tends to move at high revs , I would think from what you say you may have the cables the wrong way round .disconnect them and make sure the servo cycles first
 
It should cycle when the key is turned on after that you won't see any movement as it only tends to move at high revs , I would think from what you say you may have the cables the wrong way round .disconnect them and make sure the servo cycles first

When the key is turned does the servo motor turn both to the right then back to the left or does it just stay to the right (which is what it is doing)
 
It should turn back again leaving the flap in the exhaust in the open position. I would take the cables off first and see how the servo behaves
 
It should turn back again leaving the flap in the exhaust in the open position. I would take the cables off first and see how the servo behaves

Ok so if the servo doesnt turn back to the left, and there is no movement from the exup at all, how can i tell if the exup is open or closed and can i rig it so it always open so i can at least ride it?
 
It's been about 5 years since I removed my stock exhaust but I'm fairly sure the exup is opened fully (held by a spring) when not being controlled by the cables, so you shouldn't need the cables installed if you want a free flowing stock exhaust.
 
It's been about 5 years since I removed my stock exhaust but I'm fairly sure the exup is opened fully (held by a spring) when not being controlled by the cables, so you shouldn't need the cables installed if you want a free flowing stock exhaust.

Yes but if the servo motor turns to the right to close then back to the left to open at startup, what do you do if it doesnt go back to the left and its stuck on closed?
 
Yes but if the servo motor turns to the right to close then back to the left to open at startup, what do you do if it doesnt go back to the left and its stuck on closed?
What ballmead is saying is if you take the cables off the flap will default to the open position. I took the cover off mine and used a piece of wire to make sure the flap stayed in the open position. I use my stock can like a slip on & never connect the cables, it does nothing for performance only noise control at high revs
 
What ballmead is saying is if you take the cables off the flap will default to the open position. I took the cover off mine and used a piece of wire to make sure the flap stayed in the open position. I use my stock can like a slip on & never connect the cables, it does nothing for performance only noise control at high revs

I understand what your saying......but if the servo us not working then how can it reset it to the default position???? Which way does the exup valve have to be turned so i can jimmy rig it to stay open somehow?
 
I understand what your saying......but if the servo us not working then how can it reset it to the default position???? Which way does the exup valve have to be turned so i can jimmy rig it to stay open somehow?

By taking the cables off . The flap will automatically spring into the open position, then cycle the ignition with the cables off and see if the servo returns
 
The EXUP valve at low RPMs is default to closed (or nearly) and begins opening at higher RPMs. After some searching, I found this explanation to be the most simplistic. (EXUP (Exhaust Ultimate Powervalve) | Yamaha Motor Australia)

Yamaha Motor Australia said:
EXUP (EXHAUST ULTIMATE POWERVALVE)
It changes exhaust tuning as RPM increases. Many highly tuned 4-stroke engines with four-into-one exhaust systems have a flat spot in the mid-range, precisely where the sporting rider needs instantaneous throttle response. This flat spot is caused by positive resonance pressure waves forcing the spent exhaust gases back into the combustion chamber during the valve "overlap" period (when both intake and exhaust valves are open). These exhaust gases dilute the incoming intake mixture, decreasing performance significantly… causing a flat spot or bog. This generally occurs only in the mid-RPM range.

At other engine speeds, the positive pressure wave arrives when the exhaust valve is closed and therefore cannot dilute the intake mixture. The EXUP system features a computer-controlled butterfly valve located in the exhaust system to regulate the exhaust pressure waves. The EXUP system regulates the flow of positive and negative pressure waves in the system to improve cylinder scavenging at all engine speeds.

The wedge-shaped valve is located at the downstream end of the 4 header pipes where they enter the exhaust collector. The valve is operated by a servomotor and is regulated by the ignition computer. Sensitive to engine speed, the EXUP valve is almost entirely closed at low RPM and gradually opens to permit unrestricted gas flow at high RPM. Improvements include smoother and quieter idle, more power at all RPMs, significant low-range and mid-range torque increases, and higher gas mileage. By gradually opening the valve as revs increase, the positive wave in the mid-range is eliminated, yet the exhaust system can "breathe" fully at high revs for maximum power.

I also found this blurb in the R1 forum that makes sense:
At around 3,000 rpm the EXUP opened to around 30%, by 5,000 rpm was open almost fully, but at 7,000 rpm only opened between 40% and 60%. From 8,500 rpm it progressively opened wide. Operation was by a servo-motor controlled by the bike's ECU, with a sensor monitoring pulley position and sending information back.

So, it may be working properly but the only way to know for sure is to separate the OEM cannon from the header and watch the valve as you slowly rev the bike up to the 8500 RPMs briefly. With the baffles in the exhaust, I don't know if there is a clear shot to see it in action. I suppose you could to the same with the exhaust end of the cables detatched and in your hand.

As for the install, a guy on the other site has this documented to the letter in this post: FZ1OA Message Board - View Single Post - EXUP Cable Routing
 
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