The Out Run game uses a low resolution video signal that is likely not compatible with SCART. (sorry North american here we don't have SCART here so I don't have more info to share about it.)
the signal output by the game is called "Standard Resolution" which is a 15khz signal. you will likely need to find an upscaler adapter (something like the GBS-8200) to convert the signal to something compatible with your monitor.