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Re: Engine Break-in



My 2 cents worth on the recent "running in" posts :

>>As for how 'hard' you ride it during the break-in period . . . that's a
different matter.  In my opinion it is foolish to exceed rpm limit that
Triumph specifies for the duration of the break-in.<<

Piston rings have different requirements to bed in quickly compared to
other components in a new engine.
     A new engine requires low revs & load to enable all the new components
to bed in to each other without damage.
Piston rings need lots of load so gas pressure gets behind the rings &
pushes them against the bore to seat them. In a motor that has had new
rings & nothing else, the best way to bed them in is to take the vehicle
out & accelerate at full throttle from 1/3 to 2/3 redline in top gear ten
times.
     With my ST I observed the factory rpm limits & put the motor under as
little load as possible ( by not lugging the motor, being in the correct
gear & only using up to about 1/3 throttle) until nearly 1000 km. Then I
started using more (but not full) throttle & took it out to the rpm
recommended by the factory.

The gearbox :
     Mine has been fine since day 1, but that is probably more of a
reflection of how bad BMW (my previous bike) 'boxes are. Nuetral is
sometimes a bit difficult to find when stopped & It does make a huge clunk
when selecting 1st from standstill, even after holding clutch in for a few
seconds.


>>Many racing engine builders assemble the pistons into the bores *dry* (no
oil at all) to ensure the seating takes place as quickly as possible. <<

     This requires a certain finish on the bores ( much smoother than a
normal honed finish). Piston rings are left dry but a drop of oil is used
on the piston skirts. After building up oil pressure in the motor, it is
started, the throttle is opened full & the motor held on the rev limiter
for 20 seconds before turning it off.
     Gives very good ring seal but I wouldnt try it on a road motor where
long ring life is desired.


Darren Mason
2000 ST
Melbourne, Australia.




                                                                                           
                    Neil Lindsey                                                           
                    <neil@radiant        To:     ST@xxxxxxxxxxxxxx                         
                    .net>                cc:                                               
                                         Subject:     Engine Break-in (was Re: Gearbox     
                    14/12/00             Stiffness)                                        
                    03:27                                                                  
                                                                                           
                                                                                           




- ----- Original Message -----
From: "Gerrit Herbst" <Gerrit@xxxxxxxxxxxxxxxx>
To: <ST@xxxxxxxxxxxxxx>
Sent: December 13, 2000 3:35 AM
Subject: RE: Gearbox Stiffness


> The reason for this is that (according to the local expert) the rings
don't
> seat properly under the recommended break in procedure, he filled the
bike
> with cheap mineral oil and advised me to drive it as hard I can for 600
> miles and then only start using the recommended synthetic oil.

There is no doubt that Triumph recommends non-synthetic break-in oil until
the first service is performed.  The only issue seems to be whether they
ship it from the factory that way or whether they rely on the dealer to do
it.  I tend to believe the latter, especially in light of the above
confusion.  If you want to do an extra (early) oil change, just make sure
you re-fill it with break-in oil.

As for how 'hard' you ride it during the break-in period . . . that's a
different matter.  In my opinion it is foolish to exceed rpm limit that
Triumph specifies for the duration of the break-in.  If you believe that in
reality takes longer than Triumph suggests, then I go ahead and baby it for
awhile longer.  The only problem with that is that it's hard to restrain
yourself.

Neil



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