The last week 'Ol Red has suffered a very slow accumulation of almost
imperceptible power loss. It's now to the point where the best it will
do is about 50 going flat out on level pavement even with the pedal to
the metal. Engine starts good, runs smooth, no missing or anything of
that nature, even at speed. No bogging down on acceleration (what little
there is now)  Besides a clogged air filter - what else might be the
source of this power loss?

Thanks.

John Rodgers