A test stand is useful. Although the fine adjustments may be different on the test stand _vs_ the plane, the coarse settings will be close.

The plus of a test stand is that it is solid and you can perform long break-in runs without worrying about restraining a plane that is wanting to go. The engine on the test stand can be placed at a convenient height and the fuel mixture needle valves can be reached easily.

I'm using my new test stand this year and the new hasn't worn off yet

The test stand consists of a 4x4 post concreted into the ground, The engine holder assembly is made up from 2x4's and bolts to the 4x4 post. It consists of a .40-.90 adjustable engine mount, a 16 oz fuel tank, a lockable throttle cable/wire, a bracket to hold the tachometer, and a glow plug clip powered by one or two D-cells in parallel. The engine is set up and mounted at the workbench, and the engine holder assembly is attached to the outside post for the engine testing. I see using different engine holders for various engines: I'll be testing everthing from .06 glow engines to 6.5 gas engines.

Ain't absolutely necessary, but it makes life easier. Give me a few days to get some photos of it...