1988 Johnson 40 VRO too much oil

T

thequietman

Recruit
Joined
Jun 21, 2004
Messages
5
Way too much.

loaded%20and%20ready.JPG


Like it drains out several ounces in my garage after a day fishing.
It loads up at idle, then cleans out and runs fabulous.
I have put over 500 hours on the motor with just lower end lube
changes every year or so, and new plugs each spring.

It starts instantly, hot or cold. Great motor.

But... using way too much oil suddenly, and when you prime it hard
with the bulb, gas leaks out of the top carb or black box thingy.
I'm not sure if that is normal or related.

I am tempted to simply block the oil line like many do, but this boat has
ran perfectly for 6 years and almost 3,000 miles with zero, zip nada problems
and less than (way less) $100 in maintenance costs, so I wouldn't mind
fixing it "the right way".

thanks in advance!

John
www.kayakfishingpro.com
 
R

rolander

Petty Officer 3rd Class
Joined
Apr 20, 2010
Messages
89
Re: 1988 Johnson 40 VRO too much oil

VRO Stand for Variable Ratio Oil pump, which means it actually rations out the oil while idleing and full throttle. It uses less oil idleing and more at higher RPM. I have heard when the pumps start going bad they can either not give enough oil or too much. I am going to guess it is the oil pump starting to fail. Maybe call a good noted marine tech in your area and get his advice. Someone that knows OMC motors really well.

But that is what I have heard in my endevors on the VRO pumps. I guess a good way to self diagnose is clamp the oil line disconnect the wires to the pump and run some premixed gas and see if the problem still exists.

When you hook the pump back up though make sure you prime the bulb a few times before putting the line back on, pump the bulb and on the last pump hold the bulb compressed and have someone put the line on so that there is no air in the feed line, then make sure you run a tank of premixed fuel as well to make sure you are using oil out of the tank and all air bubbles are gone.
 
countvlad

countvlad

Chief Petty Officer
Joined
Jun 29, 2009
Messages
439
Re: 1988 Johnson 40 VRO too much oil

thequietman said:
Way too much.

loaded%20and%20ready.JPG


Like it drains out several ounces in my garage after a day fishing.
It loads up at idle, then cleans out and runs fabulous.
I have put over 500 hours on the motor with just lower end lube
changes every year or so, and new plugs each spring.

It starts instantly, hot or cold. Great motor.

But... using way too much oil suddenly, and when you prime it hard
with the bulb, gas leaks out of the top carb or black box thingy.
I'm not sure if that is normal or related.

I am tempted to simply block the oil line like many do, but this boat has
ran perfectly for 6 years and almost 3,000 miles with zero, zip nada problems
and less than (way less) $100 in maintenance costs, so I wouldn't mind
fixing it "the right way".

thanks in advance!

John
www.kayakfishingpro.com
Click to expand...

if you pump the primer bulb and fuel comes out then you either have a leak or your floats are not working properly anymore.... have you checked for air,fuel,oil leaks?

how much oil does it use? im not sure what you mean by "Like it drains out several ounces in my garage after a day fishing." ? u should be using "several ounces" of oil after a day of fishing....

or "It loads up at idle, then cleans out and runs fabulous."??? u mean smokes at idle and then its fine? if that's the case there are a few things you could try: tuneup(carb rebuild, new plugs and wires)... there are also few small check valves that allow extra fuel thats unburned to go back in to the intake manifold... when they get clogged up the extra fuel goes straight to the cylinders and gets burned causing extra smoke....
what kind of oil are u using? apparently synthetic smokes less... but costs more...

check the timing at idle....

and ohh yeah.... just changing the lower unit oil and plugs its not enough....

every year: lower unit oil, decarb the carbs, every 1-2 years(depending on the boat usage) water pump....

if you haven't rebuild the carburetors for over 2 years now its the time....
and i cant see anything in that picture...
good luck
 
T

thequietman

Recruit
Joined
Jun 21, 2004
Messages
5
Re: 1988 Johnson 40 VRO too much oil

thanks for the input, and the list of links.

What i mean by "too much" oil is that when i get home and
put the boat away, oil drains out of the exhaust for hours.

Makes a big puddle under the motor.

On the water, it smokes a lot at idle or slow troll speed, gets
better at 5-10 mph, and when run flat-out, takes a bit to clear
and then gets up and goes 30-32 kts like it has for the last 5 years
and 3,000 miles.

no other troubles.

...and yah i guess it could be time to clean or rebuild something, but
like i said the motor starts instantly, and runs perfectly year after year...
...until this oil thing.

john
 
kenmyfam

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,398
Re: 1988 Johnson 40 VRO too much oil

thequietman said:
thanks for the input, and the list of links.

What i mean by "too much" oil is that when i get home and
put the boat away, oil drains out of the exhaust for hours.

Makes a big puddle under the motor.

On the water, it smokes a lot at idle or slow troll speed, gets
better at 5-10 mph, and when run flat-out, takes a bit to clear
and then gets up and goes 30-32 kts like it has for the last 5 years
and 3,000 miles.

no other troubles.

...and yah i guess it could be time to clean or rebuild something, but
like i said the motor starts instantly, and runs perfectly year after year...
...until this oil thing.

john
Click to expand...

Do you mean dirty looking unburnt oil out of the exhaust ????
My 140hp VRO over oiled when my pump started to fail.
 
kenmyfam

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,398
Re: 1988 Johnson 40 VRO too much oil

When was the last time the carb's were re-built ???
 
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