Removing Oil Injection on 1997 Mercury 225 Offshore

[Captain Jack]

Can someone give me step by step instructions for removing oil pump and oil sensors on above motor? This engine, as I understand it, has a stainless oil pump drive shaft with a brass hub and nylon gear and is prone to corrosion and oil pump drive gear failure if it sits for any length of time without being run. This makes me nervous as we live in VA and boat sits alot in the winter. I understand the only warning sensor is for oil level in engine mounted oil tank and if shaft drive fails there is no warning! Thanks for any and all advice.

[dingbat]

Stainless steel, brass, and nylon are used because they don't corrode. They could sit for 100 years and not corrode so this is not an issue. There is a sensor on the oil shaft so this should not be an issue either unless you don't maintain the alarm system. IÂ’ve seen far more motors blown from lack of maintenance, fuel problems, over heating, and stupid human pet tricks than from oil pump failures. Not saying they donÂ’t happen but they are few and far between.

[Captain Jack]

Thank you, Dingbat, for your input. The marina that rebuilt this powerhead before I bought the boat, said the only sensor on this particular engine, 1997 Merc 225 Offshore, is for oil level in the engine mounted tank. They thought the cause of death was the oil pump driveshaft. It is a worrisome thing and I don't see any downside to removing it.

[rodbolt]

hello the system has a drive shaft rotation sensor. its the tiny deal in the block just above the oil pump. the drive shafts were prone to get a coating of rust if neglected then at the next run the rough surface will chew the nylon gear up. on that I will agree. however with proper fogging if the motor is going to sit over 30 days I dont see a problem. but yes virginia that "stainless" shaft will rust rather rapidly is not covered with oil. good luck and keep posting

[WillyBWright]

Two downsides of removing it are drastic reduction in resale value of the motor, and excessive smoking at cold idle...I mean like mosquito-fogging smoking (That'll really impress a prospective buyer when you eventually try to sell it!). Then there's the time you're going to let somebody else use your boat and they screw-up the premix. Replaced many a powerhead from that. So by removing it, you add another slow moving inexpensive below-blue-book boat to the market, reduce the mosquito population, and put food on some mechanic's table. Sounds like a win-win-win situation to me.

[Captain Jack]

OK, so if I don't remove the oil pump, I would need to remove the carberator shroud and fog the engine after each use if I was not going again in the next month. How about if I was going in 29 days? See my point? If they are prone to self-destructing the nylon gears fron corrosion, it is a matter of time before it happens. Would it be safe to just always run the motor once a month on muffs for a few minutes? Would that be absolute protection from this happening? Thanks.

[stant1man]

Im sure i read somewhere that an outboards biggest enemy was lack of use.

[rodbolt]

hello there is no absolutes in the outboard game. running once or twice a month helps. the nylon gear was not the best idea but many dont fail. while your testing the motor once a month test the alarm system as well. good luck and keep postingand yes lack of use buys me many new pairs of shoes and pays for the farrier to do my baby's hoofs

[Kenny Bush]

I have disconnected quite a few of the older Mercs, But I would leave yours the way it is. There is another sensor on the oilpump driveshaft, so when it breaks(if it breaks) the alarm will go off. I have not seen any major problems with the oiling systems of the last 6-8 years of Merc engines. My Boats sit for up to 60 days easy over winter. I use SeaFoam in the gas tank as a stabilizer/cleaner. Works great for me... but our winters are not as cold as yours. If this were 1994, I would help you disco it, but 2004 is waist of time and oil.......

[Captain Jack]

If I elect to remove the pump and pull out the shaft anyway, is it a big deal to reinstall them if I change my mind or go to sell the motor at some later date?

[Captain Jack]

Also, if the shaft breaks, what is involved in changing it then? Can you still pull the pieces out after you remove the pump or do you have to disassemble the engine?

[WillyBWright]

All of the parts are accessible from the outside except the plastic drive gear on the driveshaft. The shaft is way too strong to break. And assembly and reassembly is pretty easy, but there is a drive sensor that will sound if the mechanism isn't turning. If there's nothing in there, there's nothing to send the signal to shut the warning module up. So then you have to disconnect the warning module. I think the overheat warning will still sound, but I can't promise that. You're really opening a big can of worms and worrying over practically nothing. They just don't fail nearly as often as one would tend to believe by hanging around here. Not even close.