Thank you SNS,I should have been more explicit.
I do understand how the impulse works, but wondered at what engine speed the impulse mechanism "retracts"
Would it continue to "trigger" at low speed tickover,say 300-500rpm or would it finish as soon as engine fired up?
I assume the strength of the springs and weights via centrifugal forces play a part, much as on an old type distributor for advance and retard.
Lister
