EXUP VALVE, SERVO, CABLES

[sugarrey]

So the reason why my bike started to sound like a 250 and lost about 40 hp was because of the EXUP valve was stuck about 1/4 open.

I have a 99 r1. Anyone have any experience in changing this? Might need some help or should I let the shop do it? They are talking about $275 in parts and at least $85 in labor.

Thoughts?

[Kim-n-Dean]

Shop manual and Ron Ayers.

Then spend all the money you saved on taking me out and buy Capt'n-n-cokes for the honeys!!!

[PROFLYER]

Pull it out. I had a 99 with the same issue. Unhook all the cables but leave the servo itself in the bike, that way it will think it's doing something. Next, pull the headers and drill out the butterfly OR turn it open and tie it open with safety wire. Either way, if you drill out the pin JB Weld the holes. Easy Peasy. What happens is after years of washing water collects right where the damn butterfly is and rusts it up. A buddy did lube it well and got it to open freely so he left his. Mine was plain jammed closed so we just pulled it out.

[BHeth]

http://www.cartestsoftware.com/fz1/exupmaintenance.html

This is on an FZ1, but shouldn't matter. Scroll about halfway down to where they start talking about EXUP maintenance. Clean that sucker, lube it, and put it back together. Easy and free. If it's totally fooked or something, number 4 in the link below is your $275 part, and you can at least save the labor. Or you can remove it, but like was said, leave the servo or you will throw fault codes to the tach (how it jumps to 7K RPM).

http://www.bikebandit.com/houseofmotorcycles/yamaha-motorcycle-yzfr1l-1999-exhaust/o/m9008sch125960

[sugarrey]

It is wired open right now. I was told there was going to be mid range issues with the power, this is what I found:

- Bike idles from 800-1300 erratic
- On takeoff bikes starves for something, air, fuel, back-pressure or
something
- Mid-range absolutely sucks
- Bike exhaust is messy, not crisp

I only have a slip-on, not a full exhaust.

[sugarrey]

BHeth, great info AGAIN. Your a regular friggin encyclopedia when it comes to fixing stuff!

[BHeth]

Removing the EXUP was a big issue with the FZR1000. Putting on a full system meant a huge flat spot in the middle. It was so hard to get the jetting right that a lot of people put the stock headers back on.

I don't know if this is also true for the R1, as I have heard it's a problem and I have also heard it is not. It isn't just on there for looks though, and removing it will definitely alter the way the bike performs.

If you take it off and it's a problem, you may be looking at additional costs like a jet kit and a dyno run to get it tuned back into shape. That could end up being as much as a new valve.

I would try to clean and lube it and see what happens. I have actually never heard of one needing replacement. They stick if they aren't maintained, but can usually be saved.

[Zach929rr]

Happy you finally found the problem mang... don't have to mess with fuel/spark mumbo jumbo.

[sugarrey]

The guy told me it was the servo? Is that possible or does this valve open with the throttle? Is there a servo? How can I check it?

[BHeth]

Yeah, there's a servo. It opens and closes the valve via the two cables that you can see when you remove the EXUP cover.

Find the cables coming off the pulley and they will lead to the servo. I don't know where it is located on the R. Maybe under the tank.

When there is an EXUP problem an error code should show on the tach. It will bounce to 7K and hold, then drop and do it again. Have you seen this?

If you need to replace the servo, check the bay or ask around. They can be had pretty cheap in used condition and aren't known to be failure prone. Lots of people pulled them when they installed full systems so it isn't too hard to find someone that has one sitting around collecting dust.

[sugarrey]

So I am sick of riding this bike with the EXUP not working and am starting to dig in (nothing else to do with this weather). So I get on the gas hard and notice that one of the cables are moving, but not sure if the other one is.

Does anyone know the correct behavior of the cables when on and off the gas? I was told that the valve was stuck at 1/4 open, but was also said that I may need a servo and cables....Would like to break it down and figure it out exactly.

Any help would be appreciated.

[Speedwagon]

If it uses the same servo as my '94 YZF750, you are welcome to plug mine in for a test run. My exhaust is completely aftermarket, and I don't have the EXUP anymore(though the servo is still there to make the engine run right). But it can easily be removed for a temp install on yours, assuming it is the same. Mine is under the tank, on the right side frame rail.

Currently, my bike pulls good once I pass 4k rpm. Under that, it sucks, but I have some more tuning to do with the carbs. I suspect float height is a problem on mine, which I haven't checked yet.

[brennahm]

There's some copper lube that you should use to grease/maintain the butterfly. My 05 fully cycles the servo right when you turn the ignition (not the motor). That's a good way to check if the servo is working. You should see the cable ends cycle in and out.

[sugarrey]

ahhh......let me go out and check to see if it cycles when the ignition is turned on