Yes.....
Yeah jr. I think it's good to run it. That way, your not running more oil than you need. It's not costing you extra money in oil. Pre-mixing is a lot more expensive to run than using the injection system. But, you need to keep an eye on it. With that age, you need to test it to make sure your volume and pump is working sufficiently. You also need to make sure that it is syncro'd properly with your carb(s)........
If you look in the manual, you'll find this procedure. In turing the oil pump, I made an adapter with a piece of round stock and my dremel to cut a 1/8" slot in the end so that it would fit in my drill motor. You spin the oil pump counter clockwise to get oil flow. It's hard to figure the rpm they want you to spin, but you can at least look at the volume your pumping.
The Rotax variable injection system chages the ratio of oil to the demands of the engine. If you premix 50 or 40:1, you'll be using more and probably smoking more while the engine is running............:cheers: