Hello and thanks for your interest,
Yes it happens in both directions, and that eliminates a lot of your suggestions but don't give up on me.
Fast or slow, yes inertia caused I agree but what. Just for kicks, it doesn't do it all the time...wonderful or is that wunderbar?
When it dies it just stumbles and stops unless I goose the gas, after the turn is complete Fuel. fuel. fuel?
I have filled the tank and placed dry gas in it, no change.
The only check valve that I know of is in the outlet of each(?) pump
Stopping in both directions kinda kills all of these.....don't it?
Nuts!