ER27 Motor Timing

[Devans850]

I have an Er27 motor on an airboat that I just acquired and it won’t crank. I wanted to check the timing but there are no timing marks on the flywheel at all. I did see the timing marks on the cam sprockets and the timing belt covers. Question is, I need to replace the timing belts but how do I set the timing with no marks on the flywheel? I understand how to set the cams up but not sure about the crank. Any help would be greatly appreciated.