I have a Raritan Crown Head, I took it home, took it completly apart and cleaned it. Found that it was really in good shape. I replaced the Joker valve with a 3 way instead of the single split and it worked well for about 2 months, even taking (poo well), then it started having a really hard time flushing. It even has a hard time flushing water. I snaked the entire line. I then replaced the entire 1 1/2" line to the tank, replaced the vent, replaced the water lines on the toilet, and rinsed the tank vent line out. I'm now down to staring at the black water tank wondering if the intake line should not have a 90 degree on the line where it enters the tank. Should it be a straight line in? It currently is a 90 degree elbow right before it enters the tank. I am wondering if that is slowing it down or clogging it down. Also should the new line go up hill shortly behind the toilet and then back down to the tank for higher gravity pull towards the tank? Mine looks like this picture but my hose goes into the tank with a 90 degree elbow instead of straight in like this picture The set up in my boat is a refit from factory because the factory was a pump toilet and these are electric, so somewhere a long the line someone put these in. So if someone knows how they should be installed properly, you advice would be appreciated.