Does anyone understand how the oil injection system works on a 1987
Mercury?

Is the oil reservoir manually refilled periodically or is it an overflow
from the oil pump?
I had an alarm going off today. When I raised the float, the alarm shut
off. I topped off the oil reservoir and the alarm remained silent.

I found the line from the reservoir to the mixer cracked. Replaced it
and all is well.

Now I need to know is the reservoir there in case the oil injection
fails or as a standby for the external oil tank?

How do I know the oil injection system is working?

Inquiring minds want to know.

John

"Midlant" wrote:
Is the oil reservoir manually refilled periodically or is it an overflow
from the oil pump?

Don't know about small Mercurys but on large ones, the external tank
is supposed to keep the internal (under the cowling) tank full. Keep
the lids tight and hoses in good shape.

Now I need to know is the reservoir there in case the oil injection
fails

If the oil injection fails, the reservoir won't help matters.

or as a standby for the external oil tank?

IIRC, oil is pumped from the small (internal) tank to the mixer. The
small tank is simultaneously refilled by the large (external) tank.

It's been awhile since I've looked at the manual but I'm pretty sure
that's right. Theoretically, you shouldn't have to refill the
reservoir. Don't forget to check it frequently though (cuz $#!t
happens).

How do I know the oil injection system is working?

The warning horn is loud enough to wake the dead.

Rick

On Jul 25, 8:19 am, wrote:
"Midlant" wrote:
Is the oil reservoir manually refilled periodically or is it an overflow
from the oil pump?

Don't know about small Mercurys but on large ones, the external tank
is supposed to keep the internal (under the cowling) tank full. Keep
the lids tight and hoses in good shape.

Now I need to know is the reservoir there in case the oil injection
fails

If the oil injection fails, the reservoir won't help matters.

or as a standby for the external oil tank?

IIRC, oil is pumped from the small (internal) tank to the mixer. The
small tank is simultaneously refilled by the large (external) tank.

It's been awhile since I've looked at the manual but I'm pretty sure
that's right. Theoretically, you shouldn't have to refill the
reservoir. Don't forget to check it frequently though (cuz $#!t
happens).

How do I know the oil injection system is working?

The warning horn is loud enough to wake the dead.

Rick

I am not the original poster.

I have a 1995 115hp Mercury outboard. It also has a small internal
oil reservoir. When I bought the boat with the outboard, I don't see
any external oil tank. Seem like the internal oil reservoir is all I
have. Does this mean that the internal-link-to-external-oil-tank
combo is only for very large outboard? Does this mean that my 115hp
outboard probably is too small for an external oil tank?

Any idea? Thanks.

Jay Chan

jaykchan wrote:
Seem like the internal oil reservoir is all I
have. Does this mean that the internal-link-to-external-oil-tank
combo is only for very large outboard?

Yes. For the V6.

Does this mean that my 115hp
outboard probably is too small for an external oil tank?

Yes.
..... same for a 125hp.
They're both inline 4 cylinder engines with only an internal oil tank.
No external tank.

Rick

wrote in message
...
"Midlant" wrote:
Is the oil reservoir manually refilled periodically or is it an overflow
from the oil pump?

Don't know about small Mercurys but on large ones, the external tank
is supposed to keep the internal (under the cowling) tank full. Keep
the lids tight and hoses in good shape.

Now I need to know is the reservoir there in case the oil injection
fails

If the oil injection fails, the reservoir won't help matters.

or as a standby for the external oil tank?

IIRC, oil is pumped from the small (internal) tank to the mixer. The
small tank is simultaneously refilled by the large (external) tank.

It's been awhile since I've looked at the manual but I'm pretty sure
that's right. Theoretically, you shouldn't have to refill the
reservoir. Don't forget to check it frequently though (cuz $#!t
happens).

How do I know the oil injection system is working?

The warning horn is loud enough to wake the dead.

Rick

I'll add that if you have ANY doubt, mix your gas 50/1 in the tank till you
sort it all out. Too MUCH oil never killed anything - better safe than
have blue parts.

-W