Lorn writes:
> When I fly lean I have a lot of engine vibration because I
> am not injected. I can see my whole right wing vibrate because
> of the engine. I then enrich a little to stop most of the vibration.

The engine is running rough (presumably) because the fuel is not
distributed the cylinders evenly. A relatively easy way to ensure
uniform fuel distribution is to use injectors that can be adjusted
to match each cylinder (ala GAMI). But that's not the only way...
carbureted engines can also run smoothly lean-of-peak (LOP).
I don't know of any obvious way to adjust the fuel distribution
in a carbureted engine, but adjustments to the induction path
can have the right effect. On my O-320, there is a flow
straightener mounted at the carb inlet in the airbox. It is
slightly assymmetric. It can be installed in four possible
orientations. It turns out that one of those orientations
results in pretty good distribution, allowing the engine
to run smoothly LOP.

Has anyone else experimented with fuel-flow balancing
on single-carburetor aircraft engines?