Maybe not relevant to this but, I have a penn 555 that had a very slow spool straight out of the box.No matter what I did I just could not get it any faster.. till the other day when servicing it I tried tightening the frame bolts in increments (like torquing a cylinder heads bolts).The spool is now superfast, my only conclusion is that the plastic frame was distorting due to uneven tightening.