Oil injector discharge line connections?

I bought my friend's 1997 Rotax 503 DCDI w/Oil Injection. It was taken apart. I'm putting it back together.

My question is about those 2 discharge lines that go from injector to carbs. Which one is connected to the PTO side carb, which one is connected to the FAN side carb? Or, does it not matter?

Edit: I think the real question is: Does the injector have a timing? Should it not inject at each cylinder's intake phase?

Thanks