I took the cylinder off my tomos a3 to change rings. The piston is a little scored from grit, but the cylinder is smooth. But it looks like there's grit in my crankcase. Every time I spin the crank around, it comes back with a little grit on it. My hunch is that a I need to crack the case open to clean that grit out, or it's going to end up in my cylinder and scratch the piston/cylinder more. Am I right?