Re: [ST] Engine buzz and balance shafts

["Brian D ." <brd@xxxxxxx>]

On Sun, Apr 18, 2004 at 08:04:03AM -0400, David Pullen wrote:
> Hey everyone,
> 
> I've begun to notice a distinct buzz from the engine, especially at
> certain RPMs.  I can feel it in the foot pegs and the clip-ons; after
> a while, my heels go numb and my right hand starts to ache.

I know the feeling.

> I have talked to other bike owners (other brands of bikes), and a lot
> of them attribute similar problems on their bikes to improperly
> adjusted balance shafts.

I suppose it's possible.  I think with the Concours, for example, you
can adjust it, but not on the sprint.

> So, my questions to you guys:
> 
>   - Does the ST ('03 model) have balance shafts?  (I would assume so,
>   but you never know)

It does.

>   - Has anyone tried adjusting them to smooth out the engine?

I did research it.

>   - How do you adjust the balance shafts on our engines?

Split the case and line up the gear on the balance shaft with the gear
on the crankshaft.


My ST had a lot of vibrations, even after synching the throttle bodies,
which helped a little, and getting a new chain.  I had my local dealer
ride it and he said it was "normal" and within the acceptable range.
Even if the bike were under warranty, Triumph would not cover any work
going towards attempting to reduce vibrations.  

He did say that if the balance shaft had jumped a tooth, perhaps caused
by a backfire or something, it would be so bad as to be almost
unrideable.  I said that I considered my hands remaining numb for days
after long trips to be almost unrideable, but he assured me a jumped
gear would be immediately obvious.

But then again, my ST had an engine rebuild before I got it, so who
knows what they may have forgotten which caused the vibrations.  I would
try a t-body synch, as others have suggested.  Also, how many miles on
your bike?  How do your plugs look?  Ever had a valve check?  Check your
chain tension--if you've recently adjusted it too tight, it can
seemingly amplify engine vibration.  

Olympia gloves with GelPad palms are great for reducing numbness and
fatigue, BTW.


In contrast, my H*nda benefits tremendously from a carb synch.  The
slight vibration it had at certain RPMs went away almost entirely.  I
frequently find myself commuting in 4th and 5th gear because I forget to
upshift now.

Laters,
Brian
- -- 
Ft. Worth, TX
'97 VFR 750 (red, of course)
'99 Sprint ST(black, RIP)

     *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
      The ST/RS Mailing list is sponsored by Jack Lilley Ltd.
          http://www.TriumphNet.com/st/lilley for more info
   http://www.TriumphNet.com/st for ST, RS and Mailing List info

=-=-=-= Next Message =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=