Re: Dead engine

["Bird, Garry" <BIRD@xxxxxxx>]

I had this happen to me twice last year.  Took the bike to the dealer and they went through it and found nothing out of the ordinary.  So, I'm thinking, if everything is as it should be, why would the bike stall?  I have a theory...  My bike stalled, both times, when I was slowing down and pulling in the clutch for a downshift above 3000 rpm.  Hmmm, 3000 rpm.  How about the fact that this fuel injection system uses a stepper motor which supplies air for the idle circuit.  This would be because the main throttle body, when in the idle position, is closed tight...no air to engine.  The engine has to get its idle air via the stepper motor.  Perhaps the stepper motor (idle circuit) is off line above about 2500 rpm.  When pulling in the clutch at an rpm higher than the idle circuit is active, the engine rpm drops too quickly before the idle circuit can cut in and thus, the motor stalls due to a lack of air/fuel mixture.  I haven't had it happen to me since now I always keep the throttle just a tiny bit above idle when doing any down shifting.  (Ever notice when you are slowing down, in gear, with the throttle shut off that the engine seems very "dead" until 2500 rpm when it suddenly sounds like it "cuts in"?  That'd be the stepper motor (idle circuit) cutting in???)

Hey, it's a theory...

 -----Original Message-----
> From: Ludo Andries [mailto:ludoandries@xxxxxxxxxxxxxxxx]
> Sent: Monday, May 15, 2000 5:00 AM
> To: st@xxxxxxxxxxxxxx
> Subject: Dead engine
>
>
> Hello all,
>
> Sunday during a trip a strange thing happened.
> Whilst approaching a crossing I shifted down and closed the throttle.
> Suddenly I heard that the engine was 'dead'. Very scary !
> I had enough rolling speed to cross safely. I pushed the starter button
and
> my engine immediately fired up.
> Did anyone had the same 'problem' or any idea what could be the cause of
> this malfunction?
> TIA
>
> Ludo


Garry
bird@xxxxxxx


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