Have a 2010 rxpx255 I was replacing the flywheel bolts today and I took off my water pump housing to see no plastic impeller, but on the back of the plastic housing that comes off, it looks like a puddle of plastic that is heated up to the point of melting to the plastic housing. The previous owner had open loop cooling so there was a block plate in front of the water pump housing where all the tubes normally run I guess. Ithis normal to not have an impeller at all? my ski has never overheated or had any problems and generally runs cooler than my closed loop.