Well, I always thought that most of the oil injection systems were very messy. Trying to add oil to those remote tanks is messy, and the tanks get stinky after awhile. Mixing the oil with the gas is easier for me, and you always have a little bit of gas from the nozzle to clean up any oil spills on the boat deck or tank top. Needless to say, you must be very careful mixing oil, especially in larger onboard tanks, this operation should not be trusted to others or dock attendants.
One of the few advantages to the OMC oil injection system is that it is very simple, no mechanical pumps/machinery to worry about. The OMC system does have an oil flow alarm as well, to let you know if the system is malfunctioning. Unfortunately, the sensor can not tell the difference between oil and water. Water is one of the biggest problems for all these remote tank systems.
The other OMC advantage is that it is simple to deactivate, no pumps to remove or mechanically disable. Simply remove the oil tank, plug the fitting, and unplug the oil alarm. The problem with disabling these systems is that dock attendants asssssume the engine is oil injected, and don’t add oil to the gas.
The downside to this system goes back to its simplicity, diaphragms and flimsy plastic pieces make the pump a bit delicate and sensitive to fuel quality.
The decision to use or not use this system is mostly a personal preference type of thing. Some boats do not have a clean/dry place for the oil tank, so the system should not be used in open boats. Keep in mind there is no need to replace the VRO/oil injection pump with a conventional fuel pump if you chose the to disable the system. The VRO/injection pump works just fine as a fuel pump only without having oil flowing through the oiling section of the pump. Needless to say, it is cheaper to replace the VRO/injection pump with a conventional fuel pump if it fails as a fuel pump. The VRO/injection pumps are rebuildable though, much simpler to do than those little OMC fuel pumps!