Re: [ST] Vibration & wrong tune

[David Hom <dhom88@xxxxxxxxx>]

I recently had a problem where I was feeling
progressively worse vibrations starting around
4500-5000 rpm and my ST was running rough at low
speeds.  

I had the additional symptom that it would
occasionally misfire at low RPM.  This would occur
mostly in stop-and-go traffic where I would be in
first gear, roll-off throttle, allow the engine to
break, then slowly roll-on throttle.

Anyway, the problem turned out to be a loose hose from
one of the throttle bodies into the idle air control
valve.  It wasn't even fully off, just loose enough to
lose vacuum.  Instant intake leak...

Once slipped back on, the hesitation at low RPM and
vibration at higher RPM was gone.

Dave

- --- Sean Baumann <seanbaumann@xxxxxxxxxxx> wrote:
> 
> >Thomas Emberson wrote:
> >
> >How about something as simple/mundane as dirty fuel
> injectors?
> >
> >Is this a valid assumption, anything that causes
> the cylinders to
> >fire non-uniformaly will cause vibration?
> 
> Let me try and explain the vibrations I am feeling.
> I know I am not crazy, I 
> left a friend sit on it and he also felt them.  So,
> when the bike is 
> standing still and in neutral, I rev it up to about
> 3.5k to 4k rpms, and you 
> start to feel fast vibrations in the seat and tank. 
> It's like the 
> vibrations you feel when you are are using one of
> those cheapo random 
> sanders at a high speed.  Then when you rev the bike
> to over 5.5k or so 
> rpms, you feel it in the seat, the tank, and the
> foot pegs.  The footpeg 
> vibration is fast enough to make your feet fall
> asleep, the rest of the bike 
> feels like a two-stroke weedwhacker with the
> throttle ride open....still 
> very fast vibrations.  It doesn't feel like the bike
> is out of control at 
> all, it is just very uncomfortable.  I do feel a
> little vibration in the 
> bars, but it isn't as bad as the rest of the bike.
> 
> The bike seems to ride ok, and the power seems down
> a bit...but that may be 
> because it has the stock exhaust again.  The idle is
> not as smooth as it 
> once was, and it seems kind of hesitant at low rpms.
> 
> thanks,
> Sean
> 
> '00 Triumph Sprint RS
> 
>
_________________________________________________________________
> MSN Photos is the easiest way to share and print
> your photos: 
> http://photos.msn.com/support/worldwide.aspx
> 
> 
>      *   *   *   *   *   *   *   *   *   *   *   *  
> *   *   *   *   *   *   *
>       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


__________________________________________________
Do You Yahoo!?
HotJobs - Search Thousands of New Jobs
http://www.hotjobs.com

     *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *   *
      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 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=