How does petrol keep ?

[beggargoutel]

All,

Acquired this boat with outboard, recently.

Quite a lot of petrol in the cans. Could have been there for 3 years!!

Should I use it ?

Thanks in advance. /forums/images/graemlins/confused.gif

 

[sailorman]

made a profit already then /forums/images/graemlins/confused.gif
try it in the lawn mower

 

[Norman_E]

Yes. Too expensive to throw away. There are products sold to "revive" old petrol, but I have never found them to be required. They are probably on a par with snake oil.
One old lawn mower of mine sat with petrol in the tank for about five years. I scrapped it and poured the petrol into another mower, which started and ran without any trouble. It is just possible that a high performance engine might have a problem if partial evaporation has resulted in a reduced octane rating, though I do not know if that actually happens. If you are doubtful use the petrol for the lawn mower, or add it to the tank of your car (unless it is two stroke mix) and buy fresh for the outboard.

 

[pelicanpete]

I had some old left over 2-stroke fuel and I poured it one can at a time into the tank of my car with no ill-effects. Many years ago people used to add 'Redex' (a.k.a. oil) to their petrol as an upper cylinder lubricant, so, if anything, it might do your engine some good.

 

[VicS]

If they are metal cans and they are full and have been stored somewhere reasonably ccol then they may be Ok but three years is stretching it a bit. Don't risk it with part full cans or fuel in plastic cans, mix it with some fresh stuff and use in in the lawn mower or the car.

Try some but <u>filter it first</u> and probably better if mixed with some fresh stuff.

 

[Blue5]

I would not use it and certainly not in an outboard. Petrol does degrade I have had problems with leaving for as little as six months in small Honda engines. If you have an outboard and are not planning to use it overwinter or for a prolonged period the best option IMHO is to drain the petrol from the tank and carb

 

[Guest]

It keeps badly if in average cans in a warm place.

It keeps excellently in sealed cans that do not admit light and kept cool.

Modern Gasoline is a blend mixture made up of many different compounds, some give increased octane (potency) others give it anti-oxidation qualities etc.

Modern gasolines do have a tendency to "gum" if left in average style containers - as the light affects the blend and causes precipitation of solids. These solids often are a result of octane boosters or C5 - C9 compounds in the blend.

If the gasoline still has that typical gasoline aroma - nowadays nowhere near as sweet as it used to be - then it should be ok. Best use is to blend it off with fresh stock - but certainly not necessary to throw away - unless you wish to be charitable - then you can pass to me and I will use it gladly.

And before anyone asks - Diesel is even better at keeping and is not so prone to the gumming up.

Reason for sealed container and cool .... to reduce vapour losses which carry light-end components.


The sticky carbs etc. that many people quote are often due to a) 2T oil left behind that has "gummed" with evaporation of gasoline, b) gasoline gum that has settled out on evaporation and oxidation during such evaporation. It can be hard to remove and we use light-end components in lab to do so. Eventually it can result in a tough varnish like residue that is difficult to clean. So it is good policy to run an engine dry to stop this happening ... or drain of the carb manually. (Please don't shout at me that Engine manufacturer says not to run dry ... )

 

[Mirelle]

Thank you.

"Seagull + diesel car = half a gallon of 10:1 two stroke left over at end of season"!

 

[Guest]

Up to 5% in the diesel will burn ok ... 2T won't make any odds in diesel. 2% is good for winter.

Me ? I keep petrol in container in transom locker away from light ... present stuff is over a year old and I expect no trouble from it.

 

[oldharry]

Re: Mixing fuels - DON\'T DO IT!

[ QUOTE ]
Up to 5% in the diesel will burn ok ... 2T won't make any odds in diesel. 2% is good for winter.



[/ QUOTE ]


NO NO NO NO NO! Unless your diesel is at least 5 years old!

Modern diesels will not tolerate even small amounts of petrol. It wrecks the seals and the entire fuel system may have to be replaced in some cases. A modern Common rail injection Landrover engine for example can set you back 7 grand if you put petrol in. Merc injectors will be ruined, to quote but two examples.

If like me you run an 80s designed engine, then no probs. My old Perkins ran briefly with 35% petrol following a fuelling cock up, until we cold get back and sort it. Made some funny noises, but survived!

And don't put 2T mix in your petrol car either you may destroy the cat.

 

[jimi]

My outboard started first time last weekend with the petrol in it after hanging uncovered on the pushpit over the winter. LAst time it was used was last October. I'd just use it

 

[Guest]

Re: Mixing fuels - DON\'T DO IT!

.... but in fact company's have been putting Kero and other stuff into Diesel for years incl. Gasoline to cure winter problems. It is common to have up to 2% high grade kero in some diesels.

I don't disagree with you .... but I also know the other side of the coin from our own work in blending and analysing the stuff.

I did not advise putting 2T in a modern gasoline car - that is a no-no with the cats etc. Even the old practice of Redex is frowned on..... or as it should really be called UCL.

The only time I can fully agree with you is if the diesel as supplied is already "heavy" with kero or gasoline spike before you add yours.

If you lived out here with -30C winters etc. and you car is difficult to start etc. - you too would add a touch of gasoline .... as the Oil Co's don't add enough - it's expensive additive.

I'm lucky - I have the proper stuff to add - which sorry to say has some potent stuff in including in some additives Heptane. Now if you think gasoline is potent - try Heptane !!

 

[ShipsWoofy]

I wish you would not use the PBO forum to talk real world sense Jimi. Obviously someone heard somewhere that old petrol will destroy engines, especially none primitive high tech lumps like outboards.

If I followed the advise often given on here concerning petrol kept in cans for my 2-stroke I would be filling the outboard each time it needed it from the pump.

There must be a lot of petrol thrown away by boaters on the Sath coast, I wonder if I could pop down with my brand new tanker each spring and pick it up. This is one of those times you should not read the manual, since in my example, my 2-stroke wastes more fuel than it uses I really think the advise given about chucking it to be, well OTT.

I wonder if those giving this advice have ever thrown perfectly good fuel away or they just think everyone else should abide by their poor laboratory advice?

 

[oldharry]

Re: Mixing fuels - DON\'T DO IT!

Try doing a Google search on "Petrol in diesel".....

quite worrying if you run a recently designed diesel.

And the comment about not putting 2T in the car was really answering Pelicanpete's suggestion.

 

[Guest]

Re: Mixing fuels - DON\'T DO IT!

I didn't argue about the engine and later designs ..... but I do take issue about the matter of petrol in diesel - as it is a practice that has and is still going on ........ and considering other stuff that is put in - Heptane, Pentane, Kerosene etc. - it's the least worry.

I have posted on this subjecrt many times from the Fuel Lab side - which is the foundation of above. I am not about to instruct my labs to change based on a Google search - but will when the Oil Traders change their blending.

No-one here is reccomending regular or widespread dosing of diesel - but getting rid of odd bits or improving Cold properties is common.

A googl;e search could turn up many different worrying matters .... depends what argument you want to support !! /forums/images/graemlins/tongue.gif /forums/images/graemlins/grin.gif