[Ducati] Which 900 engines had the bad studs

[Ronald Betts]

I guess I have to add my 2 cents worth. As a automotive tech for over 25 
years (now retired) I replaced lot and lots of head bolts which would eguate 
to Studs on a motorcycle. The reason for the replacement was due to the fact 
that the bolts were a expendable part,. The reason was , the bolts were 
designed to stretch with the heating and expansion of the head in relation 
to the block. In the case of Studs it controls the stretch due to the 
expansion of the head and cylinder. Repeated stretch cycles would require 
the replacement of those bolts. Some of them are even rifled to help with 
the stretch. As far as the question of lube on the threads is concerned I 
found that using any lube gave me a false torgue reading leading to bolt 
failure as it would always cause over tourqeing. I am from the school 
(meaning comebacks and poor longivity of repair made) that taught you to 
take the time to make damn sure that the threads in the block were clean dry 
and in good shape. That meant alot of running a tap in the bolt holes as 
part of assembly prep. Once I started doing this the comebacks became non 
existant. This is the procedure used by every top machinest I have ever 
talked to including Pops Yoshimura and the wrenches in the NHRA pits. I may 
be wrong but the evidence is clear to me, Don't Lube the Threads as it will 
lead to a false torque reading.
And now, let the arguing comence!


Peace...Ron"Desmohead"Betts 95 900 SP
I've learned that I don't suffer from insanity, I enjoy it!





>From: Rich Roberts <bigredxrunner at yahoo.com>
>Reply-To: Ducati Owners Group <ducati at ducati.net>
>To: Ducati Owners Group <ducati at ducati.net>
>Subject: RE: [Ducati] Which 900 engines had the bad studs
>Date: Mon, 1 May 2006 16:08:15 -0700 (PDT)
>
>Uh okay...what does that mean, fastener is designed to stretch to give you 
>the torque? Interesting, since threads are a big part of that torque as 
>well as the amount at head, the thing that always scares me about such 
>things is exactly how do you standardize the procedure of torquing, how 
>much lube on threads, what kind of lube etc etc. As we all know lubrication 
>changes things in a big way. Use too much or the wrong kind and torquing 
>becomes an exercise in futility until that waisted section breaks. Do you 
>work in the aviation mechanics field? Where do you see such fasteners 
>routinely?
>
>frugalyankee-cycles at yahoo.com wrote:  Some of the 'waisted' fasteners I've 
>worked with over the years are the 'stretch' type (torque to yield).....
>
>Brad
>CT.
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