-Go to auto zone or preferably pep boys (auto zone tends to always be out of stock on stuff)
-Compression tester will run you $20-$30
-Take out the pin that sticks out in the hose with some needle nose pliers. This is conected to a check valve inside the tube.
-take a dremel tool or small drill bit and drill up intot he tube to open up the the valve by drilling through it.
- make sure you get all of the metal/dust out of it-blow through each end to make sure the tube/hose will flow both ways and your done
A rotary engine compression tester is completely different from a piston engine one. Might give you a rough idea , that's all. Go to the dealer and have them run a sheet for a record of your compression.