Keep Oil injection or Not!

[MarKim 2016]

I have recently acquired a 1992 Ranger 481V with a 1992 Mercury XR6 150Hp . This boat was a barn find, owner passed away, and it is in like showroom condition, boat has been hardly used. QUESTION is, I've been advised to Elemanate the Oil injection system and pre mix the oil in the gas tanks. Should I do this or not? Was told that the warning system would warn you that the oil injection is not working properly, but by then it was to late. I thought I should leave it alone and mix the gas in the tank also, so if the oil injection did shut down, the oil would still be mixed. I do realize that I would be double oiling, but didn't think it would hurt. All comments welcome. Thanks.

[Jus10]

I've got a 95 200 XRi and I removed the oil injection. Mercury makes a kit to remove the system. I heard the same thing about a failing oil injection system failing wanting you when it's too late, and figured I might as well just make the small investment to protect the motor.

[tedwards26]

If you put in the gas you know its in there

[merczilla]

I had oil injection fail me one time on a motor and i vowed never again.

The very day my warranty expired on my promax in 2000 I jerked it out installed the block off kit and never looked back. I always pre mix and probably always will. The kit is easy to install.
I use the pre mix bottles and fill em up before I leave the house, it's to easy to pour in the gas tank.

[rgsauger]

Yank it! Mix 50:1 under 6,000 rpm. 40:1 if turning over 6k. Hard to beat Pennzoil xlf.

[luvdmymerc]

Double oiling would NOT be a good idea at all. Your motor will tend to carbon up, which can cause all kinds of problems. Too much oil can also clog the jets in your carburetors and prevent proper lubrication of internal engine parts. I would recommend you visit with Don Weed, one of the Mercury guru's and see what he would suggest.

[John Jackson]

I would keep the injection. Most injection failures are blamed on the gears when the real culprit is the lines getting old and brittle, cracking, and not delivering the oil. Replace the injection lines every 5 years and is should live longer than the motor.

[sanannbassman]

I just went through this with a 'new to me' motor. 99 EFI that had no beep beep alarm when i turned on the key. So many on the boards said to remove it and mix the gas but there are drawbacks to that with the ratios, but you can do it. I replaced the oil sensor module and replaced the oil pump motion sensor for $50 and now everything is working the way it should. if the oil pump fails, you will know with the alarm. if no oil is flowing from the external oil tank to the engine tank, you will know. Without the injection, it is guess work when pre-mixing, which is not a major issue, but can be. Yes it is more parts that can fail. It all depends on your perspective and whether or not you want to deal with premixing for a motor that requires different ratios based on RPM. Just my opinion.

[JOE54]

^^^^^ also from engine that are not serviced regularly [w/p] ran hot,set up check valves stuck, or warnning system neglected ,not working, i know of many 84 and 85 model engines still with inj. running today, just a thought

[MarKim 2016]

Thanks for the replies, I feel like I need more comments to make a unanimous decision. Thanks, hope I can get more replies.

[larryhyco]

Ask Don his opinion

[merczilla]

This is what I use, it takes any guess work completely out of the equation.

[EuropeanAM]

^^^^^ also from engine that are not serviced regularly [w/p] ran hot,set up check valves stuck, or warnning system neglected ,not working, i know of many 84 and 85 model engines still with inj. running today, just a thought

+1

Proper maintenance is the key. And many times- we see "single cylinder" failure blamed on an oil pump- usually by someone that has no idea what is the "real" cause.

In ALMOST every failure case- there would be NO QUESTION, as the damage would be engine-wide (for the most part).

I prefer to retain the oil injection (and properly MAINTAIN it) on engines that will turn 6000 RPM's or below. If the engine will be spinning substantially above 6000 RPM's... pre-mix may be a viable option.

In my 39 seasons... I've seen 9 times more failures on Pre-mix engines than I have on oil injected models.

Sure... any oil injection system "could" fail. However... so can the fallible human with a mixing cup in his hand. The "human factor" is often less reliable than the mechanical device.

[90 5.0]

The early premix systems were horrible and prone to failure due to the weak plastic drive gears. On our XR-2 when it was new we lost two power heads due to oil injection failure. First one was warrantied iirc second one was not and it has had the injection off of it since at least 1989 or 90 and has never had a failure since.

The Xr-6's have a more durable drive gear I believe, so properly maintained at its rpm range it should be ok. For peice of mind however I would not own any 2.5 with oil injection but i like to run them pretty hard. But this is my personally preference I have t had any motor failure due to improper oiling in 25-26 years now. Knock on wood.

[90 5.0]

This is what I use, it takes any guess work completely out of the equation.

Thats exactly what I use.

[moetorola]

If servicing the oiling system I would replace the check valve for the oil at the fuel TEE.
In my service manual it only mentions this part as a 2psi check valve that's it, it does not say to test it as a regular maintenance item. May be different in OEM mercury manuals. The job of this check valve is to keep gas from flowing into the oil pump.

Part #5
http://www.boats.net/parts/search/Me...nes/parts.html

This part has nothing more than a spring and a needle valve in it. Just like carburetor needle valves wear out so can this part.

When it allows fuel to back feed in into the oil line past the check valve, especially when priming the pump bulb. Your engine will not get any oil, until the gas is pushed out.
It is also possible for it to backfeed and push gas into the oil pump while fishing for awhile engine off. My guess is since the fuel pump output was under pressure, if needle valves are in good working order in the carbs no gas will flow there, if the pump bulb is good it cant flow back to fuel tank, The fuel pump has valves in it, but I haven't seen one that does not allow the pressure to bleed off to the input side. The only place any fuel under pressure can go is to the check valve for the oil system if its leaking.

There will be NO ALARM that this part has failed or leaking. Because the on board oil tank will stay full, and if you have rotational sensor on the oil pump, the oil pump is still rotating, so no alarm is triggered. But your engine will not be getting the correct amount of oil, because the oil line is filled with straight gas (in my case gas and a little air was in the clear line to the oil pump).
And the gas is not pushed out very fast out of the oil line in fact it is much slower than you would think. You could already be on plane and running 5600rpm, but the oil pump has not pushed the fuel out of the line and pumping straight oil in to the fuel system.

Ask me how I know this!!!! I am know running premix!!!

I have 2 brand new check valves I ordered, but decided to go premix, after I found my oil cap alarm was intermittent. If anyone wants a check valve PM, ill take what I paid.

[MarKim 2016]

Don, please run down the proper maintenance on this 1992 XR6 150hp oil injection, Please. Thanks.

[EuropeanAM]

Most important: Use the RIGHT oil in your system. Mercury or Quicksilver Premium Plus is an excellent choice.

I would recommend (at least annually):

-Verify remote oil tank is CLEAN, and the pickup screen is free of debris

-Inspect remote oil tank lines and connections

-Inspect all under-cowling oil lines. Use the squeeze/pinch/bend test method.

-REPLACE any lines that are hardened, brittle, cracked, or opaque (bleed system afterwards)

-Inspect oil in engine-mounted tank, verify no fuel in this tank.

-If there is ANY reason to suspect fuel in the lines or engine-mounted tank, REPLACE DELIVERY CHECK VALVE

-Verify there is no air in any of the clear oil lines (If any were replaced, the system MUST be bled while run on pre-mix)

-Ensure no air is present in the engine-mounted tank.

-Verify functionality of the oil warning system (varies from one model to another- though the engine-mounted tank sensor is essentially identical on most 2.5 carb or EFI models, prior to 2001.

[MarKim 2016]

Thanks for all the replies. This site is full of answers. Awesome!

[ClaytonHaske]

Could you install a engine shut down module, so, you will get a warning sound, and the engine will automatically shut down.