Piston skirt trimming

Sometimes, with the way these little engines are put together, the piston doesn't completely clear the intake port.  This means reduced flow.  How can this be solved?  By simply trimming the piston skirt to clear the intake!  If you're looking for a little extra power increase, this might be a good answer(if you're careful not to trim off too much that is).  HeadSmess on motoredbikes.com shows how this is done, along with a few other changes like widening the ports.