Unleaded Fuel Shelf Life

[Leicester Fisheagle]

I will probably be putting Fisheagle into "winterisation mode" in November until March as circumstances this year are unlikely to allow me down again for any lenght of time. I still have a 25 litre spare tank of 4 stroke, 12 litres in the main tank and a small amount in the auxilliary engine tank. These are in tanks that are not that too easy to empty as the filler is towards the middle. I could put the fuel into my car ( its been on the boat for about two months) or I could leave it till next March. Is it true that the fuel will deteriorate if I leave it? Hoping that as winter approaches this question may be of interest to others.

[Coddy]

Hi

 

The most important thing to do with unleaded petrol is not to let the contents be exposed to the air.

If your tank can be made air tight then I would top the tank up and shut it down air-tight and you should not have any problems.

 

If this is not possible I would try to syphon off any excess and put in the car or go on a harbour trip out and use as much as possible, Poole harbour speed limits will soon be lifted for the winter, October I think, so could be an excuse to go for a fish and blast around before it gets too cold!

 

Coddy

[daz]

just out of curiosity coddy when do they increase the speed limit in the harbour and what speed is it increased to and when will it be put back to normal ??

 

thx

 

 

FISH ON!!!

[duncan]

Daz

 

1/10 through 31/3 the main channel only but right up to the start of the Frome excluding the section past Brownsea Castle out through the entrance.

 

In practice whilst people slow down from buoy 20 through the entrance they still seem to stay just on the plane at around 13 knots.............although they shouldn;t obviously.

 

 

Re the unleaded I have to disagree with Coddy's recomendation. I agree with everything he says apart from topping up the tank now. It's either sealed or it isn't overwinter and I would rather add a fair amount of fresh fuel in March than have a whole tank of potentially stale.

 

However overall I think the issue is overrated and I wouldn;t worry at all over a few months - especially winter ones! Leaving it July /August on a trailer would give rise to a bigger issue (but as most know it's not a problem)

[great white]

Stale fuel seems to give smaller engines more problems than larger ones

 

2 strokes can suffer more if the fuel is left in the bowls of the carbs over winter

 

due to the fuel evaporating and leaving the oil to go hard in the needles and jets which leads to poor starting and running in the spring

 

 

 

If it were me I would get as much out as possible and put it in the car, when the engines are winterised make sure the carbs are drained off after the engine is stopped

 

In the spring top the tanks up with fresh fuel on top of whatever is left, and the percentage of old fuel will be low and insignificant.

 

Charlie

[Mike Fox]

Advice for those using marine diesel, especially in large, vented metal tanks is to fill the tanks up as far as possible.

 

The reason is that air will get in, and damp air will condense inside the tank on the cold metal walls. The drips will work down to the bottom of the tank, and will be sucked into filters etc.

 

I have a fuel/water separator fitted with the primary filter for this very reason, and can drain any water off.

 

When I changed to a plastic fuel tank, the problem was much reduced, but not completely eliminated.

 

Mike

[duncan]

Indeed Mike - and the water / fuel interface in the tank provides a healthy environments for the dreaded diesel bug to multiply.

 

Whilst the primary will seperate off the actual water the byproducts of those measly critters play havoc with the filters themselves!

 

On the other hand diesel has a significantly longer open shelf life than petrol so there isn't any other issue to be balanced against 'full tanks all the way'.

[Coddy]

Re the unleaded I have to disagree with Coddy's recomendation. I agree with everything he says apart from topping up the tank now. It's either sealed or it isn't overwinter and I would rather add a fair amount of fresh fuel in March than have a whole tank of potentially stale.

 

However overall I think the issue is overrated and I wouldn;t worry at all over a few months - especially winter ones! Leaving it July /August on a trailer would give rise to a bigger issue (but as most know it's not a problem)

Hi Duncan

 

I light of your points I would have to agree with your comments and stand corrected. I know I was thinking of condensation problems but accept that a fresh tank of fuel in the Spring is probably a better situation.

 

Sorry for my duff thoughts.

 

Coddy

[gaffa]

I can confirm Unleaded Petrol Goes Off

 

I have a 136 litre stainless steel tank on Reflections 2 and had a situation whereby the engine continuously missfired .

 

This was diagnosed as contaminated fuel .

 

At this time the tank was about half full and had to be emptied,the petrol dumped and the tank cleaned and refilled .

 

An expensive operation at

[Leicester Fisheagle]

Thanks for the comments from everyone. Very helpful.