Doesn't the 375 Sprint use the same idle speed as all the other small B&S engines - that is, 1750 RPM? B&S say that you mustn't run them slower than that because the cooling air flow won't be sufficient. That is why they design their governors to only operate at 1750 or higher speed (1750 RPM is no kind of idle - it's quite fast enough to mow the lawn if you've got 4 blades or walk fairly slowly).
