I've been flying my GP 40 Stick for 2 seasons now.
I notice that at the top of my loops and Cuban 8's. That
the plane would roll slightly at the begginning of the down
line.

I was giving the Stick a good cleaning (glow snot) and
found the outer right Aileron hinge (ca) was broke in to.
I'm pretty sure this was the culprit to the sudden change
in flight characteristics.

So it does pay to do maintenance regulary, JMO.

Bob