View Full Version : clutch slip

10-08-2003, 09:46 AM
My Tuono has just over 1000mi on the clock. Last night I was on my way home from the local Tues night gathering. When I grabbed a HAND FULL of throttle from about 7000 rpm, I felt the clutch slip along with seeing the tach needle "bounce up" and back down as the clutch caught hold again. I was able to repeat this at will.
IS this common? Bike is under warranty. Should my dealer replace clutch or at least be the person to "scuff" the plates for me?


Tuono Tex
10-08-2003, 02:55 PM

You are sure it was clutch slip and not tire spin.

What gear were you in and how fast were you going?

10-08-2003, 02:55 PM
1K miles sound a little bit early for clutch failure...
What kind of oil did you put in there ??

10-08-2003, 03:14 PM
I thought of that as a possibility. But that usually is accompanied by a little lateral movement at the rear (wiggle). Right?
The road was dry and it was about 53 degrees out.
I was in 4th or 5th gear on the highway.

I have Motorex 15w50 organic oil! Put it in myself at 600 mi.
I didnt bring the bike in for initial service yet.

Tuono Tex
10-08-2003, 03:22 PM

Probably not wheel spin in 4th or 5th.

Can I get personal????

How big is BigGlen?

I would sure take the bike in for the first service. The most important thing they do is check the valve clearance. It's ok to do the oil changes yourself. But skipping the service is not going to help a warranty claim, if you need to make one.

10-08-2003, 03:34 PM
I fully intend to service. After all its paid for already!

BigGlen is 6'5". 240lbs


10-09-2003, 03:34 PM
Pull the check valve in the vacuum line that goes to the slipper clutch diaphragm. If you can blow through it in both directions it is bad. My friends Mille had a similar problem, we replaced the check valve with the one from his canisterectomy and it has worked fine ever since.

10-09-2003, 05:25 PM
I have the same problem on my 2001 Mille R. Bleed a little bit of hydraulic fluid at the clutch slave cylinder (open the bleed screw with slight pressure on the clutch lever then tighten the screw before releasing the pressure on the lever). Works for me.

10-09-2003, 09:20 PM
The check valve is fine.


I dont see how bleeding the clutch would help.
Can you explain why that worked for you?

Do you mean "bleed air" or do you mean to just release some hydrolic preasure?


PS: I bled the clutch really well last week Before this started happening? (bled air)

10-10-2003, 08:17 AM
When the clutch is slipping, I can not feel any free play at the clutch lever. I bleed a small amount of fluid (no air that I can tell) and the free play is restored and no slipping clutch. I only ride the Mille on track days and have had to do this maybe three times out of a total of less than 20 track days.

I've never had this with any other hydraulic clutch and so far have not seen anything similar on my Tuono.

I have read a lot on this board about slipping clutches on Milles with all sorts of expensive repairs suggested. Try bleeding a little juice, it works for me.


10-10-2003, 12:28 PM
[QUOTE]Originally posted by GeneS
>> Try bleeding a little juice, it works for me.<<

THIS is a VERY interesting possibility. Hmmm.

Maybe the Aprilia clutch can actually be pumped up TOO firmly (like from a good bleed). Consequently, it will have some EXCESS hydrolic pressure in the system that aplies slightly against the push rod. This then prevents the clutch from being a full 100% locked. Remember, I just happend to have flushed the clutch fluid last week and bled and pumped up the the lever really good. In fact, I noticed that the engagement point moved up at the lever to wear in acts on the slave cyclider as soon as I move the lever through its first 3/4" of travel!

And what youre saying to do is actually release some fluid from the bleeder in the slave cyl end of the system.

I CANT WAIT to test this out! My wife is gonna freak when as soon as I get home from the office, I'm disappearing in the GARAGE!