Re: removing merc 2001 vro
I guess it's a misnomer of sorts on what Merc's oil injection really is or what it's called. It is a variable ratio as published data indicates that it adds oil to the gas at a ratio of 80 parts gas to 1 part of oil at idle and this "varies" up to 50:1 at WOT. So you have a "variable ratio oiler". By using premix you just run a little richer (oil richer) at the low rpms. I did my 90, using syn blend TC-W3 oil and I can't tell the difference in smoke nor performance.
Best way to answer your question is to get the parts manual for your engine. Seloc manuals on here can be rented for about $10 per year and are accessible 24/7, or you can buy the paper. You just log in and look through the index for what you want. On the oiler in my engine, my OEM Merc manual did not mention the innerds of the pump, just showed and referred to a pump. The Seloc had a sectional view/parts breakdown format that showed the pump, the gear, and the bushing(s) that need to be removed......they don't tell you that but if the gear is gone, they may decide to go also, later on, who knows when, and you don't want that. In checking the parts breakdown you can see if anything else needs to come out on your engine.
Mine was a matter of removal of a hose that was in the way, undo two bolts, pull out the pump, remove the gear and prise out the retaining bushing and reinstall. That's it. The pump is apparently a displacement pump as you need accurate accounting for the oil pumped. Being such, if the gears are not turning, no oil is moving through the pump. So (opinion) you don't need to do any bypass plumbing unless you just want to. You can watch the oil level in your tank and if it should start to drop then ok, the pump is leaking and you need to block off the outlet hose to the fuel line (on mine). Course the easiest thing to do would be to put a little clamp on the outlet line and squeeze it shut.
So, I reinstalled my pump with 2 bolts, put the hose back on, had half a tank of oil which I just left in to satisfy the low alarm and that was 6 months ago. 0 problems.
HTH,
Mark
