Aqua Magic V Problem

You do not state if your 3 inch down pipe from the floor to the tank is STRAIGHT down. If it is, you can shine a Flashlight when opening the toilet flush ball and see if there is a blockage. IF your downpipe, makes a angle and you cannot see the tank, odds are that down pipe is clogged at one of the ABS pipe angles. ALL a RV toilet does is dump the sewage to the down pipe and tank. There is nothing on the toilet that will cause diminished output to the dump hose. UNLESS the area above the floor Flange is clogged which is easy to see. I would run a cheap HD/Lowes spring type snake down thru the toilet. You only have to go about 1 to 2 feet depending on how high the toilet is above the tank. IF it does not make a easy smooth shot down, you will have found your problem AND can use that snake to then fix the problem. Doug