On May 8, 7:39*pm, Bertie the Bunyip wrote:

another useful clue

The deflector business is something nobody else has mentioned yet;
I'll pass it on to the A&P. He's got a couple planes needing
attention to their engines and the Citabria, being under-utilized and
still flyable in the pattern, isn't a high priority, so resolving this
may take until next week. I'll post what's been found after the whole
system's been gone through thoroughly. Thanks.