Oil leak near exhaustpipe

[Tamburinifan]

Ken,
what torque f a ST2 (I have ST2 heads on mine and they leak as well)?
No leaks?

[Duc906]

Ken,what torque f a ST2 (I have ST2 heads on mine and they leak as well)?No leaks?

Do you have some leaks anymore?So, could it be enough to re-torque the leaking head?Ciao

The torque settings for a ST2 are
first-15Nm
second-30Nm,
final-38.5Nm.
The torque settings for a 906 are
first-14.7Nm,
second-29.4Nm,
final-41.2.
As you can see there is not a lot of difference between the two.I rebuilt my engine because there was too much end play in the output shaft.I found I had a problem with 1 of the heads being slightly warped but I fixed it as per higgy's directions.I didn't have any oil leaks before I stripped the engine down and so far the bike has been back on the road for 2 weeks and there is still no leaks.
With the engine cold,there is 0.3mm gap between the head and barrel,if I had my engine apart still I could have measured the o-ring recesses for you to see if there was any differences.

[Tamburinifan]

So torque seems the same, I`ve followed the 906 ones.
I have 0.35mm clearance on my 907 (& my M900 -97),
hmmm, could those 0.05 make a difference?

[jcslocum]

Make certain to follow the lubrication spec for the nuts/washers/studs. To get the proper load you must lubricate....

[higgy]

But not too much, keep those holes and surfaces dry and clean as a whistle. Lube threads only and drain excess Prefit and drain and clean again with soap and water no chemicals. Take your time and be meticulus unless you want to do it over. Had your studs out, keep those holes clean ,fluids do not compress and will throw off the torque and keep those studs too high and nuts will hit the shoulder of those studs and throw off all torque results. Also torque angle is more accurate than torque wrench unless you have stretched studs.Measure the length of those studs before you torque. All gasket surfaces need to be sharp and flat, no rounded or marred up edges.

[jcslocum]

Higgy,

Usually we are 100% on the same page. I have to disagree with you on this one tho. You must lube the face of the nut that makes contact with the washer. There is more friction in this area than on the threads themselves.

**Also torque angle is more accurate than torque wrench unless you have stretched studs.Measure the length of those studs before you torque**

I'm not sure what you are saying here. Yes, Angle of Turn can be more accurate than torque but no home mechanic will have an understanding of this and Ducati doesn't give a spec for AoT. AoT also starts with a torque value to firm up the joint before measuring AoT, so you can't get away from it!

All studs get stretched to provide the clampming force for the gasket to perfom is job and overcome any other loads induced while operating. If you mean over-stretched, measuring them will not give any indication that they have been yielded. If that has happened, you will not be able to torque them as they will have gone plastic and just keep stretching out until they part/fail. Ducati only stresses these studs to 50% of yield so even a 10-20% over-torque won't have damaged the studs. Maybe the holes in the case but not the stud. If in doubt, replace them!

I agree with the rest of what was posted. Cleanliness is next to Godliness.....

[higgy]

Technically speaking, whether you lube or not before torquing depends on how the torque value was derived, dry or wet. If wet you must use the same lube as was used in deriving the torque value and the torque value most likely will be expressed as an angle. Most non angle torques are derived dry and are friction based.

You must lube the face of the nut that makes contact with the washer. There is more friction in this area than on the threads themselves.

Exactly the point, however,Lubing the contact surface where the clamping force is applied will reduce the friction and cause over torque,every time. Never ever ever lube the washer or the nut face when using a torque driver unless specifically stated it is required by the manufacturer NEVER! Sorry Jon you are incorrect on this one. When using a torque angle gauge to lube or not doesn't enter into the value, the value when stated as an angle is based on the tensile strength of the fastener as you have stated.
You are correct about the tensile strength of the fastener being the basis for any torque setting whether expressed in foot pounds or degrees. It is all about stretch and torque wrench or angle is no way to measure bolt stretch.
When in doubt, always follow the manufacturers procedure.