Hi,
in the back of my mind I seem to recall hearing that the mixed oil and
petrol fuel as is used in outboards "ages"

Can anyone advise as to whether this is correct?

cheers,
Peter

On Tue, 03 Apr 2007 09:47:55 -0400, Peter Hendra
wrote:

Hi,
in the back of my mind I seem to recall hearing that the mixed oil and
petrol fuel as is used in outboards "ages"

Can anyone advise as to whether this is correct?

cheers,
Peter

Please forgive my insistence, but can anyone give me any idea how many
months I can keep mixed outboard fuel - petrol and oil.

It's great to know that yes, definitively, it does age but it would be
really helpful for a cruiser such as myself to know;

1. How long I can keep mixed fuel?

2. What happens when it is aged? - Does it become less useable in any
way such as clogging carburetors etc

Thanks
Peter

Peter,
A good rule of thumb is untreated mixed gas will last about 2 months. After
that it "sours", fouls the plugs, doesn't burn right etc.
I have no idea of the chemical reason for this, I just know I've used this
rule since the USN taught me to mess about with rubber ducks 25 years ago
and it works for me.
MMC
"Peter Hendra" wrote in message
...
On Tue, 03 Apr 2007 09:47:55 -0400, Peter Hendra
wrote:

Hi,
in the back of my mind I seem to recall hearing that the mixed oil and
petrol fuel as is used in outboards "ages"

Can anyone advise as to whether this is correct?

cheers,
Peter

Please forgive my insistence, but can anyone give me any idea how many
months I can keep mixed outboard fuel - petrol and oil.

It's great to know that yes, definitively, it does age but it would be
really helpful for a cruiser such as myself to know;

1. How long I can keep mixed fuel?

2. What happens when it is aged? - Does it become less useable in any
way such as clogging carburetors etc

Thanks
Peter

On Wed, 4 Apr 2007 09:25:24 -0400, "MMC" wrote:

Thanks MMC (were your parents poor when you were born and couldn't
afford a longer name?)

This is the sort of practical information that I was looking for. The
rest was just curiosity.

Have a great day,
Cheers
Peter
Peter,
A good rule of thumb is untreated mixed gas will last about 2 months. After
that it "sours", fouls the plugs, doesn't burn right etc.
I have no idea of the chemical reason for this, I just know I've used this
rule since the USN taught me to mess about with rubber ducks 25 years ago
and it works for me.
MMC
"Peter Hendra" wrote in message
.. .
On Tue, 03 Apr 2007 09:47:55 -0400, Peter Hendra
wrote:

Hi,
in the back of my mind I seem to recall hearing that the mixed oil and
petrol fuel as is used in outboards "ages"

Can anyone advise as to whether this is correct?

cheers,
Peter

Please forgive my insistence, but can anyone give me any idea how many
months I can keep mixed outboard fuel - petrol and oil.

It's great to know that yes, definitively, it does age but it would be
really helpful for a cruiser such as myself to know;

1. How long I can keep mixed fuel?

2. What happens when it is aged? - Does it become less useable in any
way such as clogging carburetors etc

Thanks
Peter

On Wed, 04 Apr 2007 04:58:22 -0400, Peter Hendra
wrote:

It's great to know that yes, definitively, it does age but it would be
really helpful for a cruiser such as myself to know;

1. How long I can keep mixed fuel?

2. What happens when it is aged? - Does it become less useable in any
way such as clogging carburetors etc

If you add stabilizer when fresh, it should be OK for at least 4
months, possibly more if stored in a cool place out of the sun.

As gasoline (petrol) ages it loses octane and tends to form varnish
deposits. Octane loss causes pre detonation and is harmful to
pistons, varnish deposits are harmful to the carburetor.

On Wed, 04 Apr 2007 10:35:57 -0400, Wayne.B
wrote:

Wayne,
Thanks for this very practical advice.

Would you be able to suggest a stabiliser? I have never heard of this
concept but then there are a lot of things I don't know about.

cheers
Peter
On Wed, 04 Apr 2007 04:58:22 -0400, Peter Hendra
wrote:

It's great to know that yes, definitively, it does age but it would be
really helpful for a cruiser such as myself to know;

1. How long I can keep mixed fuel?

2. What happens when it is aged? - Does it become less useable in any
way such as clogging carburetors etc

If you add stabilizer when fresh, it should be OK for at least 4
months, possibly more if stored in a cool place out of the sun.

As gasoline (petrol) ages it loses octane and tends to form varnish
deposits. Octane loss causes pre detonation and is harmful to
pistons, varnish deposits are harmful to the carburetor.

On Wed, 04 Apr 2007 11:41:56 -0400, Peter Hendra
wrote:

Wayne,
Thanks for this very practical advice.

Would you be able to suggest a stabiliser? I have never heard of this
concept but then there are a lot of things I don't know about.

The brand I am most familiar with is called "Stabil". It is readily
available in the US from West Marine:

http://tinyurl.com/ynma3p

I add it to the tank of my small boat when I'm going to be away for
awhile, and also add it to my emergency supplies of generator gas.

With outboard motors, generators, etc. it is good storage strategy to
turn off the fuel with the motor running until they run out of gas.
That prevents deposits from forming in the carburetor regardless of
whether the fuel is stabilized.

On Tue, 03 Apr 2007 09:47:55 -0400, Peter Hendra
wrote:

Hi,
in the back of my mind I seem to recall hearing that the mixed oil and
petrol fuel as is used in outboards "ages"

Can anyone advise as to whether this is correct?

cheers,
Peter

In my experience, "old" gas has never been a problem. By old I mean 6
months or more for mixed oil/gas and as much as 24 years old for unmixed
gas. The latter was in an old grass edger that I didn't use any more but
would start every year or so just to see if it still started. Believe it
or not!

We were sailing on Monday with a small 5 hp 2 stroke outboard
(Mercury/Tohatsu) that had not been run for 6 months and I had to crank it
5-6 times but then it ran just fine with old gas. I do clean or change the
spark plug and lower lubricant every year though. I don't use additives
such as Stabil.

Our 4 stroke 6hp John Deere lawnmower (Kawasaki engine) started last week
on the first try. It was about 1/3 full before I topped it off and started
it. My small power washer also started on the first try yesterday.

That's my experience. It seems to me that there is way too much hype about
"old" gas. YMMV

On Wed, 04 Apr 2007 15:59:38 -0500, NoSpam wrote:

That's my experience. It seems to me that there is way too much hype about
"old" gas. YMMV

Sometimes you get lucky, sometimes not.

I'm pretty religious about running my emergency gas generator twice a
year - and then letting it run out of fuel before I store it.

Forgot to shut off the fuel and let it run out a year ago, and just
recently had to have the carburetor replaced.

Expensive lesson.