>>I shudder
> to think what it would feel like to have a kick back against the high
power
> starter.
<<
Actually, no difference other than the small additional torque of the
starter and small additional inertia of the rotor (if indeed it is any
heavier or faster). The dynamics of the problem (whilst it is occurring) are
not controlled directly by the characteristics of the starter motor.
Duncan McF
PS Terrible pun!
----- Original Message -----
From: "P.A.D.Clarke" <paddyclarke@lineone.net>
Subject: Re: Europa-List: Rotax starting - 912S
<paddyclarke@lineone.net>
>
> Hi All,
> First a word of caution. I'm not an engineer and don't
have
> any specialist knowledge. What I have to say may well be ( and probably
is )
> a load of old rubbish. Having said that, I'll press on anyway.
> The problem seems to arise when the engine kicks back on
> start up. The poor little starter motor turning one way meets the engine
> violently kicking back the other. The location for this titanic conflict
is
> the sprag clutch - no wonder it can't cope. The higher output starter
spins
> the engine so fast that there is plenty of inertia to carry it over the
> compression, whenever ignition takes place. This is how it feels anyway.
> I agree that the higher power starter will put greater
> torque into the clutch, but I suspect the increased forces are relatively
> small compared to those involved in meeting a backfiring engine. I shudder
> to think what it would feel like to have a kick back against the high
power
> starter.
> Cheers, Paddy Clarke
> ps. I hope this message doesn't appear twice - we had a power cut just as
it
> was being sent!
> ----- Original Message -----
> From: "Ami McFadyean" <ami@mcfadyean.freeserve.co.uk>
> To: <europa-list@matronics.com>
> Subject: Re: Europa-List: Rotax starting - 912S
>
>
> <ami@mcfadyean.freeserve.co.uk>
> >
> > How is it that the higher power starter motor does not put a higher load
> on
> > the sprag clutch, which would lead to the earlier demise of the clutch?
> This
> > assumes that the clutch is the victim rather than the cause, which seems
> to
> > be the case.Or is it that the violent starting (and the 'standard' but
> less
> > violent stopping) is the sole cause?
>
>
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