If an air cooled has a switch on the throttle, I would check that it is
working.
Also check that the movable vane in the airflow meter is not sticking.
  Good luck,
Larry A.

On Wed, Dec 12, 2018 at 4:53 PM al sinclair <alvanagon@gmail.com> wrote:

> Thanks. Fuel filter was replaced when the rebuilt motor went in ~10k miles
> and two years back.
> If the fuel filter was flaky wouldn't that more likely lead to problems at
> higher engine power, not when starting-off from stationary? There are no
> issues with running at full bore.
>
>
>
> On Wed, Dec 12, 2018 at 1:05 PM KIM BRENNAN <kimbrennan@mac.com> wrote:
>
> > Air, Fuel, Spark. From your description it sounds like Air and Spark are
> > okay...So, when was the last time the fuel filter was changed?
> >
> >
> > > On Dec 12, 2018, at 3:58 PM, al sinclair <alvanagon@GMAIL.COM> wrote:
> > >
> > > Please help suggest a cause of a new problem in 1981 Westie
> (aircooled),
> > > automatic not stick shift.
> > >
> > > Occasionally, a few times a day, there's no response from the engine
> when
> > > pushing the accelerator pedal to accelerate from stationary. The pedal
> > > moves normally, and the sound of the engine changes so I think the
> > throttle
> > > opens, but there's no change from idle, no increase of power for at
> least
> > > several seconds. Then the engine behaves totally normally. I've begun
> > > pumping the pedal when this happens but I'm unsure if it makes any
> > > difference.
> > >
> > > The engine was rebuilt a couple of years back (lovely job by Greg
> Tuttle,
> > > installed by Fred's Garage, runs like a dream) maybe 10,000 miles ago.
> > It's
> > > had oil changes but little else since then.
> > >
> > > Any ideas how to identify the cause will be much appreciated. The
> problem
> > > isn't reproducible on demand, it only happens now and then - and can be
> > > scary if I'm pulling out across the road.
> > >
> > > Thanks
> > > Alan
> >
> >
>