With a little ingenuity, you can test your model aircraft engines on a safe, homemade platform without shelling out extra cash to buy prepackaged version. There are several ways that you can customise the platform to allow for several different sizes of engine, as well. Chances are, in fact, that you've got all the materials you need in your workshop right now.
Utilise the scrap plywood as the base plate for the engine test platform. Drill a hole through the bottom of the Popsicle stick, and another small hole through the centre. Screw the Popsicle stick into the side of the base plate to act as the throttle control. Mount the model aircraft fuel tank opposite the throttle control with sturdy rubber bands stretched over top and lashed with screws. Place the feed tube end of the fuel tank near to where the aircraft motor will be mounted. You may wish to support this on a piece of scrap 2-by-4 screwed to the base plate.
Install two scrap 2-by-4 pieces at the opposite end of the base plate from the fuel tank and throttle control. Drilling multiple holes along the base plate at varying distances apart will give you the versatility to mount several different sizes of engine. Ensure that these are mounted the same distance apart as is between the mounting points of the engine you are testing. Screw these into place securely from the bottom of the base plate. Drill small holes into the top of these to serve as screw holes for mounting the engines.
Run the fuel line from the fuel tank to the engine to be tested, then use the heavy copper wire to run between the throttle control stick and the model engine.
Avoid testing engines with propellers in place, particularly larger, more powerful engines.