100 hp Merc: excessive oil consumption
 

I have an 88 100 horse Merc outboard, oil injection. It seems to be
injecting oil at the rate of 1 litre every 1 1/2 hrs of operation. Manual
says the 4 litres should last 18 hours at WOT. It is not leaking out and
the motor is not emitting any visible smoke. It seems to run normally. The
motor is a recent purchase and I don't really know if this is a sudden
development or not.

Possibly related: Temp gauge only lifts off of 60F a bit when I boat in
warmer water. Usually it doesn't move at all. This is either a bad temp
sender or bad thermostat which causes motor to never really get warmed up
properly. Would a stuck open thermostat cause excessive oil consumption? Is
there an adjustment that can be made to the oil injection pump?

Any advice is appreciated. Vacation is coming and I don't want to tow the
boat 100 miles to the mechanic if I can avoid it.

--
Denis Roy
D. Roy Woodcraft
www.ideasinwood.com

100 hp Merc: excessive oil consumption
 

Sure it's 1988 and 100hp? I thought they had a 90 and a 115 ??

Try this........ use the boat on Vacation - THEN - tow it to a mechanic and
have him look at the excessive oil consumption.

Burning too much oil never hurt a 2-stroke in the short run.

-W



"Denis Roy" wrote in message
news:vU%Mc.114793$ek5.44429@pd7tw2no...
I have an 88 100 horse Merc outboard, oil injection. It seems to be
injecting oil at the rate of 1 litre every 1 1/2 hrs of operation.
Manual
says the 4 litres should last 18 hours at WOT. It is not leaking out and
the motor is not emitting any visible smoke. It seems to run normally.
The
motor is a recent purchase and I don't really know if this is a sudden
development or not.

Possibly related: Temp gauge only lifts off of 60F a bit when I boat in
warmer water. Usually it doesn't move at all. This is either a bad temp
sender or bad thermostat which causes motor to never really get warmed up
properly. Would a stuck open thermostat cause excessive oil consumption?
Is
there an adjustment that can be made to the oil injection pump?

Any advice is appreciated. Vacation is coming and I don't want to tow the
boat 100 miles to the mechanic if I can avoid it.

--
Denis Roy
D. Roy Woodcraft
www.ideasinwood.com

100 hp Merc: excessive oil consumption
 

"Denis Roy" wrote in message
news:vU%Mc.114793$ek5.44429@pd7tw2no...
I have an 88 100 horse Merc outboard, oil injection. It seems to be
injecting oil at the rate of 1 litre every 1 1/2 hrs of operation.
Manual
says the 4 litres should last 18 hours at WOT. It is not leaking out and
the motor is not emitting any visible smoke. It seems to run normally.
The
motor is a recent purchase and I don't really know if this is a sudden
development or not.

Possibly related: Temp gauge only lifts off of 60F a bit when I boat in
warmer water. Usually it doesn't move at all. This is either a bad temp
sender or bad thermostat which causes motor to never really get warmed up
properly. Would a stuck open thermostat cause excessive oil consumption?
Is
there an adjustment that can be made to the oil injection pump?

Any advice is appreciated. Vacation is coming and I don't want to tow the
boat 100 miles to the mechanic if I can avoid it.

--
Denis Roy
D. Roy Woodcraft
www.ideasinwood.com

As the other guy said, burning too much oil won't hurt it, most likely.
I've run a lot of 50:1 outboards with 20 - 25% extra oil (e.g. 40:1). This
is, obviously, quite a bit more oil than "normal". I've never had a problem
with this, not even fouled plugs. But I'm just one guy and your consumption
is a lot greater than this. Makes me wonder if you're seeing bad symptoms -
excessive smoke, quickly fouled plugs, poor performance?

Can you tell us how much gasoline you're burning in 1.5 hours? Then we
could calculate approximately how much oil is being used per liter of
gasoline. As you probably know, it should be about 50:1 (gas:oil). I'm not
familiar with consumption per hour specs. as I've only heard of ratios of
gas:oil.

100 hp Merc: excessive oil consumption
 

40/1 is normal (safety) mix for a 50/1 motor running 100 to 110% of WOT.

I run 40/1 about 1/3 of my operating time.

-W



"Camilo" wrote in message
...

"Denis Roy" wrote in message
news:vU%Mc.114793$ek5.44429@pd7tw2no...
I have an 88 100 horse Merc outboard, oil injection. It seems to be
injecting oil at the rate of 1 litre every 1 1/2 hrs of operation.
Manual
says the 4 litres should last 18 hours at WOT. It is not leaking out
and
the motor is not emitting any visible smoke. It seems to run normally.
The
motor is a recent purchase and I don't really know if this is a sudden
development or not.

Possibly related: Temp gauge only lifts off of 60F a bit when I boat
in
warmer water. Usually it doesn't move at all. This is either a bad
temp
sender or bad thermostat which causes motor to never really get warmed
up
properly. Would a stuck open thermostat cause excessive oil consumption?
Is
there an adjustment that can be made to the oil injection pump?

Any advice is appreciated. Vacation is coming and I don't want to tow
the
boat 100 miles to the mechanic if I can avoid it.

--
Denis Roy
D. Roy Woodcraft
www.ideasinwood.com

As the other guy said, burning too much oil won't hurt it, most likely.
I've run a lot of 50:1 outboards with 20 - 25% extra oil (e.g. 40:1).
This
is, obviously, quite a bit more oil than "normal". I've never had a
problem
with this, not even fouled plugs. But I'm just one guy and your
consumption
is a lot greater than this. Makes me wonder if you're seeing bad
symptoms -
excessive smoke, quickly fouled plugs, poor performance?

Can you tell us how much gasoline you're burning in 1.5 hours? Then we
could calculate approximately how much oil is being used per liter of
gasoline. As you probably know, it should be about 50:1 (gas:oil). I'm
not
familiar with consumption per hour specs. as I've only heard of ratios of
gas:oil.