Old Petrol and Changing your impeller

[Bigplumbs]

Well I hear so much talked on here about the supposed horrors of old petrol and also how often you should change your impeller in an outboard.

Here is a real world example. I have not used one of my speed boats for 3 years and the petrol in the tank is I suspect 3 - 4 years old. I have also not changed the impeller for over 8 years.

Last week I started the engine after it standing for 2 - 3 years with the old petrol in the tank. I had to put a new Battery on it as the previous one was about 8 years old. The engine started very well but the water was not pumping as good as perhaps it should but it was pumping.

I replaced the impeller today and the old one actually looked very good with no real signs of degradation. The engine ran fine on the old petrol.

Now perhaps this is because the engine is a 115 hp Mercury 2 Stroke or is it the case that all the old petrol chat is nonsense.

As for replacing impellers every year...... What a total waste of time, money and the planets resources.

 

[jamie langstone]

Well I hear so much talked on here about the supposed horrors of old petrol and also how often you should change your impeller in an outboard.

Here is a real world example. I have not used one of my speed boats for 3 years and the petrol in the tank is I suspect 3 - 4 years old. I have also not changed the impeller for over 8 years.

Last week I started the engine after it standing for 2 - 3 years with the old petrol in the tank. I had to put a new Battery on it as the previous one was about 8 years old. The engine started very well but the water was not pumping as good as perhaps it should but it was pumping.

I replaced the impeller today and the old one actually looked very good with no real signs of degradation. The engine ran fine on the old petrol.

Now perhaps this is because the engine is a 115 hp Mercury 2 Stroke or is it the case that all the old petrol chat is nonsense.

As for replacing impellers every year...... What a total waste of time, money and the planets resources.

I would say depending on your engine hours each year if it’s worth changing your impeller. I use my boat a lot so it gets changed . But if like you I didn’t use it that often then I Would do the same and leave it.

 

[Sneds]

Wouldn’t it get deformed and take the shape of it’s stationary position?

 

[QBhoy]

Well I hear so much talked on here about the supposed horrors of old petrol and also how often you should change your impeller in an outboard.

Here is a real world example. I have not used one of my speed boats for 3 years and the petrol in the tank is I suspect 3 - 4 years old. I have also not changed the impeller for over 8 years.

Last week I started the engine after it standing for 2 - 3 years with the old petrol in the tank. I had to put a new Battery on it as the previous one was about 8 years old. The engine started very well but the water was not pumping as good as perhaps it should but it was pumping.

I replaced the impeller today and the old one actually looked very good with no real signs of degradation. The engine ran fine on the old petrol.

Now perhaps this is because the engine is a 115 hp Mercury 2 Stroke or is it the case that all the old petrol chat is nonsense.

As for replacing impellers every year...... What a total waste of time, money and the planets resources.

I’ve got 1100 hours on my original impeller, but have a water pressure gauge reading ri check it constantly, being fair.
As for the old petrol…you think it’s possible that you may not find if it’s any good or not, until it’s ran on load perhaps ? Especially if that 115 is a 2+2 ?

 

[Momac]

I have experienced petrol going off on the basis of fresh fuel fixing rough running and poor starting.
I also found premium fuel helped with the running of an old 2 stroke outboard.
This despite the 2 stroke oil might to some extent preserve the fuel.

My lawnmower runs better of fresh fuel and better still on premium fuel.

In my 3 year old car there is no difference between premium fuel and regular fuel performance

I conclude the more modern and sophisticated the engine the better it can deal with fuel quality.
Petrol goes off quicker than it used to. eg last years fuel in a half full tank loses its charm.

If your 115hp outboard has electronic fuel injection it probably tolerates poor fuel ?

 

[SC35]

Here's another real world example.
Mercury 5hp two-stroke.

Was running okay at the end of last season, and started in the tank in March after some persuasion.
Come May, and it would not start at all - spark plug out, dried, cleaned etc.
There was a spark, but the plug just kept getting covered in fuel.
Put a fresh batch of fuel in the tank - now starts and runs easily.

 

[Bigplumbs]

I actually think you have that the wrong way round in my experience it is the older engines that tolerate old fuel better

 

[Bigplumbs]

One of the issues with the bad fuel theory is it is causing people to dispose of petrol in dangerous and ways that are very bad for the environment. Also engine manufacturers are are jumping on this and blaming it to try and get out of warranty work

 

[Bigplumbs]

Wouldn’t it get deformed and take the shape of it’s stationary position?

that is another one of the much peddled theory’s and to some extent has some basis in truth but they certainly do not need replacing every year and the one I took out has slowly reformed its shape sitting on the bench after 20 hours

 

[Bigplumbs]

Here's another real world example.
Mercury 5hp two-stroke.

Was running okay at the end of last season, and started in the tank in March after some persuasion.
Come May, and it would not start at all - spark plug out, dried, cleaned etc.
There was a spark, but the plug just kept getting covered in fuel.
Put a fresh batch of fuel in the tank - now starts and runs easily.

interesting so what did you do with the old fuel

 

[Momac]

I actually think you have that the wrong way round in my experience it is the older engines that tolerate old fuel better

I am not making it up. I am reporting facts based on my own experience.

By the way I don't dispose of old fuel but spruce it up with the addition of fresh fuel.

 

[Bigplumbs]

I am not making it up. I am reporting facts based on my own experience.

By the way I don't dispose of old fuel but spruce it up with the addition of fresh fuel.

As was I. I also had a P Reg Toyota Previa which I have converted into a Camper van stand about 4 years or more with old petrol and it started and ran on the button.

I am not saying that old fuel is good but that people should not be throwing it away too quickly and also that too many jump straight to it as a cause for there engine not starting

 

[SC35]

interesting so what did you do with the old fuel

Diluted a bit, it seems to work alright in the ancient 4-stroke lawnmower, but it's a bit smoky.

 

[limecc]

This was interesting

As part of the stabilizer test he tries to run an engine on old fuel. Pretty conclusive results.

 

[Bigplumbs]

This was interesting

As part of the stabilizer test he tries to run an engine on old fuel. Pretty conclusive results.

Not interested in Googling and copy and paste to be honest..... More interested in real life and what I have experienced

 

[SC35]

Not interested in Googling and copy and paste to be honest..... More interested in real life and what I have experienced

You prefer not to learn from other people's mistakes, instead making them all yourself?
(I do that ...)

 

[paradave]

Well I hear so much talked on here about the supposed horrors of old petrol and also how often you should change your impeller in an outboard.

Here is a real world example. I have not used one of my speed boats for 3 years and the petrol in the tank is I suspect 3 - 4 years old. I have also not changed the impeller for over 8 years.

Last week I started the engine after it standing for 2 - 3 years with the old petrol in the tank. I had to put a new Battery on it as the previous one was about 8 years old. The engine started very well but the water was not pumping as good as perhaps it should but it was pumping.

I replaced the impeller today and the old one actually looked very good with no real signs of degradation. The engine ran fine on the old petrol.

Now perhaps this is because the engine is a 115 hp Mercury 2 Stroke or is it the case that all the old petrol chat is nonsense.

As for replacing impellers every year...... What a total waste of time, money and the planets resources.

N=1