Mercury OB - oil injection system

[JoeMan]

I've debated about my oil injection system, as to whether to continue trusting it or to disconnect it. Based on a couple of reasons, I am disconnecting it, and would like to know the best way to do so. I'm sure there must be a safe way to D/C it and leave it mostly intact for when the day comes to sell the motor and hook the unit back up. If you are familiar with these, please tell me the best way.

My reasons? For starters, I notice that I'm using likely HALF the oil that I used to use with my former motor, an older Merc 60. Going through only half or maybe even less oil makes me nervous. I am not willing to take it to a mechanic for system tests, etc. It's real simple...the engine is not getting the ratio of oil it requires, and I no longer trust the unit, especially since I typically run the engine hard. Secondly, a trusted friend who runs Mercury has known multiple folks whose Merc motors were ruined due to running too lean, and the blame was associated to the oil injection system not providing enough lubrication. I know that Merc oil injection systems are supposed to be amongst the most dependable, but I'm taking no chances, and the solution for me seems really easy and very safe.

It seems to me a very simple and inexpensive bit of "insurance" to add my own oil mixture, and so I'm settled on it. I ran the old Merc OB and never forgot a single time to add the oil. To me it was as natural as putting the key in the ignition before expecting the motor to start, or locking the door on my way out of the house.

So...how to D/C this thing the proper way?

 

[Silvertip]

Re: Mercury OB - oil injection system

Many engine failures are blamed on the oil injection when in fact that diagnosis is very often wrong. Oil injection on these engines is not cylinder specific so it can't just pick one cylinder to damage. You mentioned "lean" and "oil injection" in the same sentence. Both can cause a failure but either alone can do it as well. The type of failures are different from each other. If an engine burns down because of a lean condition, the oil injection had nothing to do with it. Those are carburetion issues. Bearing failure and seizing are oil related. Detonation related failures are ignition timing related. One way to test the system is to mark the oil level in the tank with the engine perfectly vertical. Add a known quantity of oil and mark the new level. If you have a separate tank, empty it and then add the amount of fuel corresponding to the amount of oil you added so you have an exact 50:1 ratio. Now run that measured amount of fuel through the engine. The oil level should be down to the first mark you made. If not, its not oiling at 50:1. If it is, leave it alone and run it.

 

[j_martin]

Re: Mercury OB - oil injection system

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=29;gtid=1247062

Hope it helps,
Thanks Willie
John

 

[JoeMan]

Re: Mercury OB - oil injection system

Silvertip, thanks very much for the advice/suggestion. I will do my due diligence to test it. John, thanks for the link to the other thread as well.

JoeMan

 

[j442w30]

Re: Mercury OB - oil injection system

I thought about disconnecting mine (1993 40 horse 4 cylinder) but after getting some opinions from the people here I figured why mess with it. If yours is an autoblend unit then I would say disconnect it but the design of mine is simple and uses a metal drive gear. I agree that mixing gas and oil is not that bad and it does provide you with piece of mind but oil injection is a nice convience and "if it ain't broke, don't fix it." Just my 2 cents.

 

[JoeMan]

Re: Mercury OB - oil injection system

Autoblend or metal drive gear - I would not know the difference.

 

[WillyBWright]

Re: Mercury OB - oil injection system

AutoBlend was an old system that had an oil tank inline with the fuel line. It wasn't part of the motor, and it could be used on any motor that used 50:1.

I don't know what you have, but I have never heard of an oil injection failure on anything other than a V-6.

Some motors have variable ratio oiling and others are fixed-ratio. If there is a link rod to an arm on the pump, it's variable from about 100:1 at idle to about 60:1 at WOT. Pumps without arms mix at 60:1.

 

[JoeMan]

Re: Mercury OB - oil injection system

By the way, this is a 1995 Mercury 60 hp 3 cylinder outboard.

It sounds like you pros have not seen much actual failure with these systems.

 

[JimmyRD]

Re: Mercury OB - oil injection system

AutoBlend was an old system that had an oil tank inline with the fuel line. It wasn't part of the motor, and it could be used on any motor that used 50:1.

I don't know what you have, but I have never heard of an oil injection failure on anything other than a V-6.

Some motors have variable ratio oiling and others are fixed-ratio. If there is a link rod to an arm on the pump, it's variable from about 100:1 at idle to about 60:1 at WOT. Pumps without arms mix at 60:1.

I have a 90 hp , 3cyl Merc built in 1997
I just found that my false low oil warning was due to the small circular magnet on the bottom of the float inside the oil tank haveing seperated from the float allowing the magnet to fall to the bottom of the tank and set off alarm. I superglued it back on and it worked. I am hopeful, that the glue is not effected by the oil but even if another menthod has to be used I figure it's better than a replacement tank assembly ($200?) or sensor ($30? )or Module ($285?)..
I also found that, after verifying that the tank was full, a small piece of electrical tape over the "mouth" of the alarm beeper allowed us to continue the trip without noise-induced insanity. You can still hear it if all else is quiet but not so well when underway.