Oil Catch Tank

When removing the stock air filter and installing an aftermarket filter, the kart builder looses the tube that runs from the valve cover to the carberator intake. This tube removes pressure from inside the valve covers and with that comes a little oil. As a result, this tube must be rerouted. One can buy fancy, expensive oil catch tanks, but they are easily made. Some racers even use plastic soda bottles, and I originally made one by fashioning a hose barb to the mouth of a Dr. Pepper bottle. Here's another way that cost me about $15.
I started with 2" sch 40 PVC (plastic water line) with two (2) caps. In the caps I drilled a hole off center so as to be near one side. I then tapped those holes for a 1/4" MIP fitting. Using PVC cleaner and glue I fixed the caps on each end of a piece of the pipe about 8 inches long. You can paint this with plastic paint if you like, but it's not necessary. Next, I put a 1/4" MIP x 1/8" FIP reducer in one hole and a 5/16" Barb x 1/4" MIP in the other using Teflon tape on the threads. A valve with 1/8" FIP threads can then be put in the appropriate fitting. I ran a poly tube (7/16" O.D. and 5/16" I.D.) from the hose barb to the opening in the valve cover. This should also have a vent, to be updated in the near future.
The tank is now finished except for mounting. I put mine on a cross member using two pipe hangers connected with 3/8" all thread rod. Make sure to double nut this or it will come loose.