I know the injection has been removed. And yes, I am saying 50:1 is not enough oil. You should be running it at 40:1 and your carb jets have nothing to do with it. You do not have to change the carb jetting to go to premix or run 50:1 or 100:1 or 32:1 or 40:1.
Your engine needs oil to survive just like any engine, I am telling you 40:1 but you are free to do what you want.
The factory oil injection on these works great and there is no reason to remove it. The stock system is variable rate based on throttle position, at idle it is at about 100:1 and at wide open throttle it is at 32:1 which is perfect for the engine. When we break-in a new engine we run the factory injection and premix at 50:1. THey still run perfect and don't foul plugs.
And to beat a dead horse, what oil are you using to premix?