Throttle balancing problems...

[Gnasher]

You can calibrate these. With nothing connected, take of the lens and adjust the brass screw until all the gauges read the same. Once all "zeroed" you should try them all on the same cylinder to check the reading is roughly the same on each gauge. Once done, you can connect to the other cylinders to confirm if the cylinders are out of adjustment or not.

Well that's one way of doing it, I suppose But it's not calibration, that's done under various loads of a measured source, that said if you can get these to read the same consistently it will do.

You learn something every day