Tiger Moths that Suck
Reading old RAF Tiger Moth Pilot's Notes. The starting instructions tell you to "tickle" the carburettor (meaning deliberately flood it). Then the engine fitter (who is also the bloke that hand swings the propeller) turns the propeller backwards to "suck in" then turns the prop forward several times to "blow out" -then after calling "contact" puts impulse magneto switch (front knob of front switches) on the contact position and then flicks over the aircrew with one hand until engine fires.
If engine fails to start due rich mixture the fitter calls "Switches off throttle wide open- blow out".
Technical question: What does sucking in mean? And why is it necessary to suck in? Why 8 turns of the prop (sorry - airscrew!) to suck in but only 4 turns to blow out? If the carby is deliberately flooded then why not do what we do on any flooded engine - and that is throttle open and churn the prop over with the starter motor to clear excess fuel?
And why deliberately flood the carburettor - isn't that a fire risk?
Believe it or not these are serious questions as I have the opportunity to have a fly of the beast next week.