Does petrol age, go off???

[4gearwonder]

Hi all,

Don't know if this anyone's had a prob with this, but any info appreciated as always

If a vehicle has petrol in it and has been stored/not used for number years, can the petrol degrade in that time and make it hard to start despite having a good healthy spark, petrol going to carb and all those other things that should be there?

Reason I ask, the guy in the garage next next to our van was trying to start his old 50's vauxhall over the weekend and was asking the question as this is what he was experiencing

Said I would ask the good folk here if anyone knew the answer

If anyone has any ideas, then that would be much appreciated and interesting to know the answer too!

Thanks all.

[windysurfer]

Yes. Don't know why but it does.
Bought an outboard which hadn't been run for a few years, had a good spark but wouldn't start. Changed old petrol and it fired up on the new stuff

[Bogwoppit]

The chap that services my lawn mower tells me to always make sure it's empty before I put it away for the winter for this reason. He says the petrol goes 'flat' after a while.

[Mocki]

that new fangled semiskimmed, erm i mean uleaded suffers from "going off" more than the full cream, erm proper leaded petrol, dunno why,
but the 50's humber surely would have been using leaded, or at least LRp wouldnt it?

[jamesc76]

the octaine rating goes down as it evaporates, during storage hence "going off" Thats why a squirt of start pilot works on old engines as its very high octaine boost!

[hi_tower]

you can buy an additve from frost that stops this from happening. Think machine mart sells it too.

[moloko]

yes petrol does go off ,just smell and you can tell,engines run (rough)but will not start,ask any lawnmower mechanic in spring(easy money)

[4gearwonder]

Ok! Seems like it does then

Will relay that info to the man with the vauxhall next time I'm on the van.

Thanks for you replys though amigos.

Cheers.



B

[HarryMann]

the octaine rating goes down as it evaporates, during storage hence "going off"

Nah, that would make it more combustible.. octane rating is the resistance to premature combustion, fuel's viagra!

But yes, it can go 'off' - ask the army blokes.

[BenT]

Hi all,

Don't know if this anyone's had a prob with this, but any info appreciated as always

If a vehicle has petrol in it and has been stored/not used for number years, can the petrol degrade in that time and make it hard to start despite having a good healthy spark, petrol going to carb and all those other things that should be there?

Reason I ask, the guy in the garage next next to our van was trying to start his old 50's vauxhall over the weekend and was asking the question as this is what he was experiencing

Said I would ask the good folk here if anyone knew the answer

If anyone has any ideas, then that would be much appreciated and interesting to know the answer too!

Thanks all.

Petrol (or gasoline as we call it on out side of the big pond) after being stored for some time will have lost much of it's more volatile components. As a result, the fuel that has a higher flash point. In other words, it is more difficult to ignite. Besides that, some components turn in the perfect woodfinish -- varnish.

[HarryMann]

Besides that, some components turn in the perfect woodfinish -- varnish.

Yes.. and shellac? It's the carb that often suffers worst as it ages and evaporates.

And it's quite possible that leaded fuel is preserved better. There were some lead/mercury amalgam 'pellets' available as 'Octane boosters' a few years ago, that also claimed to preserve fuel over-winter. I have a few of these and for years have had one in my petrol strimmer tank, which always starts after a winter in the allotment shed - except this year, it's been 'disappeared'

They were touted as good for small outboards. Different sizes, zinc plated steel cages with 3 small or 6 large pellets, and a chain to retrieve it from the tank..
(Mercury amalgam is what common teeth fillings are made of, supposedly inert to the body, now thought maybe not so inert!)

[BenT]

Besides that, some components turn in the perfect woodfinish -- varnish.

Yes.. and shellac? It's the carb that often suffers worst as it ages and evaporates.

I don't know, Clive. I think shellac comes from the secretions of "bugs" not vans or trucks.

[HarryMann]

You're probably correct, certainly sound like it does.

Always thought it was the thicker heavier elements of varnishes, duh!

She who must be listened to says that Laphroig Scotch smells like shellac, and is yuk!

So I listened and obeyed, and drank it to get rid of the 'orrible stuff

[BenT]

You're probably correct, certianly sound like it does.

Always thought it was the thicker heavier elements of varishes, duh!

She who must be obeyed says that Laphroig Scotch smells like shellac, and is yuk!

Of course, I am BenT-but-str8! I searched the meaing of life just for you. Had to do it because I started to wonder if I was misinforming you due to some language barrier.

http://en.wikipedia.org/wiki/Shellac

BTW, do you spell "vice" as in the thing used in a workshop to hold metal things with a "C" or does that mean the same as what some workshops do around the Playboy Mansion? I wondered because someone posted "vice" for sale on this site. Of course, I was unable to prevent myself from opening the thread. To my disappointment, the fellow is selling those things we spell as vise as in grip. No, not that grip.

[HarryMann]

Apparently, vise or vice is OK for vise!
Shellac wiki, fascinating stuff.