What you call monitor is probably the picture tube?
Are you sure that monitor chassis supports vga resolutions?
It looks like a 15/28khz chassis (But I could be wrong)
Outrun 2 requires a resolution of 640 x 480, and that monitor chassis might be unable to handle those resolutions (if it's indeed 15 / 28kHz only)
Don't you have other numbers printed on the pcb like Nanao MS28 or something like that?