Exup Valve

Blavenia

Blavenia

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Okay, when the cables on the Exup valve in the GenII muffler are disconnected, the flapper is wide open.

When re-connecting the flapper valve to the cables, should the Exup valve be turned and then the cables attached so it starts off closed, or should it always be open until the cables pull it so it gets more closed?

Does this make sense?

I figure at idle the Exup valve in the exhaust needs to be fully open so it can close via the motor to produce backpressure during certain throttle openings.

I just wanted to make sure I put it back together correctly!
 
Scotty:

Would you agree from the photo that the cable on the bottom (9) should be attached to the bottom of the Servo Motor, and the upper cable (8) should be attached to the top of the servo motor? Only makes sense, right?

I can't believe I have the entire factory manual from Yamaha in a box somewhere!

B
 
Blavenia said:
Scotty:

Would you agree from the photo that the cable on the bottom (9) should be attached to the bottom of the Servo Motor, and the upper cable (8) should be attached to the top of the servo motor? Only makes sense, right?

I can't believe I have the entire factory manual from Yamaha in a box somewhere!

B
Click to expand...

Brian, Scotty might not reply for a while due to the time difference. Based on the pictures in the service manual I think you're correct. Are there any markings (i.e., 1 and 2 or Upper & Lower) on the servo motor that you can see, which might indicate cable position?
 
Ok, so I couldn't work it out from the manual as there are not enough drawings to show the servo under the seat. But after the old brain kicked in I realised I have a stock bike out in the sun drying after washing it this morning. So I took the seats off and looked, and to my surprise the bottom cable on the exup valve on the exhaust goes to the top cable position in the servo. Yes top cable goes to bottom, and bottom cable goes to top! I looked at it several time 'cause I thought I was seeing things, but thats how my bike is routed.
 
Ok, I took some pics to back this up so I know I was not seeing things. Getting old sucks man!
So, as the service manual states:
Note:
When installing the EXUP cables, make sure
they are parallel and not twisted.

The pic shows the wrong way, you will see why in my pics.

Now in this first pic you see the servo under the seat. The camera is facing towards the front of the bike, and its facing forward for the next pic too.
So, as you see the cables go around horizontally, then they bend 90 degrees and go down, the top cable goes to the outside of the bike.
View attachment 3855
It's from here that the manual refers to ensuring the cables are not twisted. I followed them down and found that they follow this configuration all the way down to where you see them in the next pic.
View attachment 3856
So, top cable on the Servo goes to bottom position on the EXUP valve.
 
Scotty:

What tremendously valuable information! Great pics, too! I can't thank you enough for going out there and helping someone half a world away!

When I removed mine, I didn't even pay attention figuring I was never going back to stock setup. Boy was I wrong.

Did you follow the cable from the bottom (black metal #9) all the way up to the top connection on the Servo motor, not just relying on the viewable position of the cables as they went from top to bottom?

What's funny is that I have it connected exactly this way as you described, bottom to top, and I thought after viewing your photo from the manual that I did it wrong. What a crazy thing, but you've saved me another 1/2 hour in the garage!

Now I just have to adjust the free play and test it out with the info from chapter 8 in the manual.

Again, I can't tell you how much help you've been, and I really needed it.

Anything I can help with, just ask.

Brian
 
NJFZ1 said:
Brian, Scotty might not reply for a while due to the time difference. Based on the pictures in the service manual I think you're correct. Are there any markings (i.e., 1 and 2 or Upper & Lower) on the servo motor that you can see, which might indicate cable position?
Click to expand...

I didn't see any markings at all on the servo motor, which is what prompted me to be so worried if I did it correctly or not.

I guess Scotty really helped us with this one by going out and looking at it in the flesh!
 
Blavenia said:
Scotty:

What tremendously valuable information! Great pics, too! I can't thank you enough for going out there and helping someone half a world away!

When I removed mine, I didn't even pay attention figuring I was never going back to stock setup. Boy was I wrong.

Did you follow the cable from the bottom (black metal #9) all the way up to the top connection on the Servo motor, not just relying on the viewable position of the cables as they went from top to bottom?

What's funny is that I have it connected exactly this way as you described, bottom to top, and I thought after viewing your photo from the manual that I did it wrong. What a crazy thing, but you've saved me another 1/2 hour in the garage!

Now I just have to adjust the free play and test it out with the info from chapter 8 in the manual.

Again, I can't tell you how much help you've been, and I really needed it.

Anything I can help with, just ask.

Brian
Click to expand...

My pleasure Brian. I'm more than happy to help someone out that can appreciate the help and not take you for granted. Thats one of the things I love about this forum.
Ah, yes I intricately followed the cables all the way down. When I did it i even partially removed a rubber hose that runs down with the cables to make sure I wasn't getting mixed up. And thats what the 'Note' is talking about in the service manual.
 
scottyd said:
Too easy Brian! I just bought the service manual CD off ebay for $10 this week, happy to be able to use it! :)
Click to expand...

I'd like to get one of those manuals too. I went to ebay and there were several to choose from. Which one did you get Scotty?

Thanks Bluey
 
I'm thinking of re-installing the original muffler, but I lost the servo. Could I just re-connect the muffler with out the servo or cables?

would I be hurting anything?
 
You can... so long as the EXUP is in the open position. You may want to figure out how to insure that it will never close. It wouldn't hurt anything unless it did close. :D

Also, you can post up a wanted ad for the servo since some have removed them like yourself. You have the eliminator plug installed?
 
Yes I have an eliminator plug instaled from Graves. I'll try to close the valve by hand to see how hard/easy it is to close. I migh have to ruig something up to keep it open.

Good idea to look for a used servo. Thanks
 
After reading your question, I figured you could simply block the exup from the outside near the spring from being able to turn by screwing in a bolt where the cables would normally hook in to hold it in place.

Hold the valve open by removing it's ability to close in the same location as the pull cable would be in. Instead of connecting the cable there with the tension adjusters, connect a threaded bolt there that the Exup will hit on the outside if it tries to open or close.

Should be a .50 cent job and completely effective.

I figured since Scotty went out there for me, I went out and looked and you can see where a long bolt threaded through the cable mount to a nut would block any movement of the Exup valve.
 
Last edited:
Perfect guys. I'll take a look tonight and I'm sure I have a bolt/nut that will work. The saftey wire is also a great idea.

Man I love this forum! I'm hopping i will get experienced enough one day to help somebody out with advice.
 
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