I have a fuel injected EFI and I still unhooked the factory oiler, on my Mercury I had to go in and pull a little pump pin, only took about 30 min. to do it...... I have never trusted the oilers, I have over the years ending up running a little rich, looks like I am fogging for bugs when I fire it up, but $16 a year for new plugs is a cheap price to pay to be sure oil is getting to the engine and it is going on 16 years of trouble free service......