I pulled my lower unit off my motor last night to replace water pump(1st time to do this). When I pulled the lower unit loose from the motor, a chunk of painted aluminum 3/8"x3/8" fell onto the floor. I check everything out that I could see and could not find anything. Could it have come from inside the engine compartment and made its way into the exhaust??? It looks like it did break off from something, maybe it was just from manufacturing.
I don't know model or serial numbers, but it is a 2004 225HO 25" shaft DI, not an ETEC

Thanks, Brad