Removing oil injection on a 1990 150 v6 mariner 2 stroke??

[burleygu]

Have been going over my 150 mariner ready for it to be refitted to the haines once its ready to go. And I want to remove the oil injection on the motor. For a few reasons mainly to eliminate the chance of a oil pump failure as I don't know enough about the engine or its service history.

So firstly is this a good idea and is it safe to do?

I plan to run 50:1 which I will just add the required oil to the tank every time I fill up. Pain in the ass yes But if I stuff it up I only have myself to blame.

Secondly is it as simple as cutting the oil line between the reservoir and oil pump and block each end of the hose. Or will the blockage of the oil pump feed line cause other issues? (see in red circle) Keeping the oil reservoir under the cowling full to eliminate the low oil alarm going off?

Any advice or information appreciated

Cheers Tim

[Steeler]

If coin is not an issue why not consider an electric operated pump version which can be fitted to these motors. A good option if you like the conveniance of the oil injection.

[caravellerob]

My 98 175 efi Merc has had the oil injection system removed completely from under the cowl. I pre-mix in the tank at 50:1 and I reckon mine smokes less than the oil injected two strokes down at the ramp and it certainly smokes a lot less than my old 90 hp merc I had which was oil injected. It is a pain to add the oil when I fuel up 300 odd litres but it's a small price to pay for knowing the oil is getting in the motor. I would have a look on the yanky sites like the hull truth as they would tell you the best way to go.

[burleygu]

Ive not ever heard much about an electric version? My understanding was that the oil pump delivers different amounts of oil less oil at idle more at higher rpm's etc that's another reason I wanted to remove it as Id rather have the engine receiving oil at all times. Does the electric version operate in the same manner? Id much rather mix the oil in the fuel myself

[burleygu]

My 98 175 efi Merc has had the oil injection system removed completely from under the cowl. I pre-mix in the tank at 50:1 and I reckon mine smokes less than the oil injected two strokes down at the ramp and it certainly smokes a lot less than my old 90 hp merc I had which was oil injected. It is a pain to add the oil when I fuel up 300 odd litres but it's a small price to pay for knowing the oil is getting in the motor. I would have a look on the yanky sites like the hull truth as they would tell you the best way to go.

I didn't want to completely remove the oil injection more so just disable it so if I was to ever move the motor onto a new owner and they wanted oil injection everything would be there for them to make it operable.

[caravellerob]

To be honest bud (don't take this the wrong way), I don't believe you de-value a motor of that vintage with or without the oil injection system fitted.

[Steeler]

Ive not ever heard much about an electric version? My understanding was that the oil pump delivers different amounts of oil less oil at idle more at higher rpm's etc that's another reason I wanted to remove it as Id rather have the engine receiving oil at all times. Does the electric version operate in the same manner? Id much rather mix the oil in the fuel myself

http://www.marinesolutionswi.com/

[burleygu]

To be honest bud (don't take this the wrong way), I don't believe you de-value a motor of that vintage with or without the oil injection system fitted.

Don't stress mate as far as im concerned when im finished with it the motor may be worth 500 bucks either with or without the oil injection. I personally would prefer to disable it. Where as someone else may prefer re using the oil injection.

So is it possible to disable the oil injection as described in my first post without causing any issues?

[caravellerob]

not too sure bud, have only heard of people taking it off completely.I found this on marine engine.com.
Mariner oil injection.disconnect

Yep - drain the oil tank and remove the line between the tank and the oil pump. You can plug the hole on the tank where the line was and just leave the tank there.

Now, disconnect the line from the oil pump where it T's into the fuel line (just before the fuel pump). Take the end that was connected to the T and connect it to the oil pump (where the line from the tank used to be). It's a good idea to fill it with oil before you reconnect it. Then plug the inlet where the oil used to feed to the fuel pump.

By simply looping the oil line back to the pump with oil in it, the oil pump will sit there "happy to pump oil" that is going nowhere other than back to itself. That allows you to leave the oil pump in place.

It also means that if you ever sell the motor to someone else who is not afraid of the oil pump failing, they can easily reconnect it.

[Mr__Bean]

My opinion and experience after removing oil injection from a 1988 200 hp Black Max V6 Mercury, which I think is the same system.

As the oil pump is mechanical you must remove the oil pump drive shaft if you are going to do this, otherwise the mechanically driven oil pump runs dry and will fail causing other engine problems.

I did it after getting an annoying oil alarm, it was a cheap fix rather than fixing the oil sensor but I wouldn't do it again.

The oil injection system regulates the amount of oil added to the fuel depending on throttle setting, low throttle less oil, more throttle more oil.

After I removed the oil pump drive shaft, tank and hoses I ran 50-1 premix.

At mid to high thottle the engine ran fine but at idle and constant low throttle the engine oiled up and ran rough.

I would often have to go to neutral and give it a rev if trying to troll or stay at low revs in gear (cruisingup to jetties etc).

Accordingly I wouldn't do it again.

Darren

[FisHard]

The rig I've just scored has a 96 mod 150 Mariner and it's had the oil injection removed. Not being the mechanical type, I'm not the bloke to tell you how it was done, but I was surprised during the test run, how well it ran. The owner had also been running 50/1.

[Noelm]

Leave it on! It is good simple system, gives little trouble.

[Roughasguts]

Leave it on! It is good simple system, gives little trouble.

Yup leave it on!!!!

If you are worried about it failing carry 1 litre or so, of tcw3 in the locker and be prepaired for it to get dusty.

But if the oil pump does fail pour your 1 litre of oil in the fuel tank, and if you have 50 or so litres in there you now have a pre-mix of 50:1 easy huh.

It wouldn't hurt to do a few stop starts! to slosh the oil around then prime the fuel bulb in too an empty container just to get the oil up the the motor, then pour it back in to the fuel tank, to clear the oil from the fuel tank neck.

Cheers.

[ozscott]

I dont know much about the Merc injection. I know with the Yammy V4's they are 200:1 at idle. I would have thought the Merc was at least 100:1 at idle. I cant understand the poster above that mentioned he pre-mixes and his is cleaner than most of the oil injected's at the ramp. It may have to do with the oil he uses, but I would never go back to pre-mix provided the system is reliable.

Cheers

[Steeler]

Leave it on! It is good simple system, gives little trouble.

Thats Mercs in general Noel, thats why they get a coat of black paint. The troublesome motors , well they get a inbuilt countdown timer and a splash of white .