The injection system can be tested by adding oil to the tank and continue to use premix fuel while observing for leaks, the cable to the carb/s should move with the throttle, find your pump sync marks on a photo - then mark them with something because they are hard to see on the linkage - I use nail polish dots on each side of both halves, the variable oil injection allows reduction of oil at idle and low speed to preserve spark plugs based on the minimum load on the power plant, when you increase throttle the oil increases to preserve the sliding and rotating parts from failure as the power demand increases. at times the mixing of oil causes gel in the pump and small lines, not knowing what the previous user had used for oil it makes sense to add kerosene to the oil tank and let it work thru while running on premix like you have been, you will see some more smoke when the goo goes thru and the kerosene drops from the tank, at this time you can remove the tank and wipe out with old shop cloths or run it out as you have fun riding, then add the oil that you can find over a long duration and stick with it, mixing is what makes the oil system fail. In the beginning of each season mark your oil tank while running on 5-6 gallons premix and when you observe the oil being used then just add gas and go, the extra oil is good for the motor that sat idle in storage and you already know how to mix gas so enjoy.
