Charles wrote:
> The HIF series SU had a heat-sensitive jet positioner which
> leaned the mixture when the engine was at operating temperature in order
> to reduce hydrocarbon emissions. Because there is an additional device
> moving around inside the HIF series the mixture and idle speed are not as
> "set" as it is with the HS series.
Not quite. The jet positioner in the HIF is in the float bowl. It adjusts
(minorly) the jet position by the temperature (and thereby, sorta, viscosity)
of the fuel. You actually get a more stable fuel mixture throughout the temp
range.
The typical cause of inconsistant idle speeds is those damned poppet valves
in the butterflies. Smogged HS*'s suffered from the same problem.
Randy
randy@taylor.infi.net
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