Stale petrol

I had a problem with my Norman T300 at a rally last year - it just stopped and despite everything I did it refused to start - much to the amusemet of the spectators!When I got it home I checked the plugs again,timing and carb settings - still no joy.I returned to it several times over the succeeding months topping it up with petrol with no success.Then the spark disappeared - took the mag off and cleaned all the connections - spun it over by hand on the bench and got quite a belt and lovely big strong spark - put it back on the engine and the spark was there but reduced - no idea why as the surfaces between the mag and the engine were clean.Tried to start the engine - nothing. Then at last the penny dropped - stale petrol!The system was drained and fresh petrol put in - after 3 swings it burst into life - what a great sound!I felt a right wally for not realising that the petrol was to blame.
I have heard of petrol giving problems but never come across it myself.The petrol I was using was purchased last june ( doesnt time fly!) and works fine in my Lister D but the Norman doesnt like it.
All the best,
Kev.

It's odd how some engines don't like stale petrol, never had it myself and we have some kit that isn't run for 6+ months at the stables, the quad and mower are parked up over winter and start fine in spring, the opposite is the generator does nothing all year until the nights start closing in and we need it for lighting, that just needs a jump start so it can charge it's own battery.
Just remembered my can of Petrol/oil mix for the strimmer must be 2-3 years old as it uses so little, maybe the oil has something to do with it?

Stuart.

Not had a problem with my engines as I drain them for the winter. However some my items of garden machinery were a pig to start in spring as I can't seem to fully drain them even when I run them dry.
Briggs & Stratton Fuel Fit seems to help.

I always leave tanks as dry as poss for this reason.

I know people say that condensation is more of a problem but I ignore that.

The ethanol in modern petrol is quite corrosive to older metal parts and swells older rubber parts.

I agree with Woody and drain as much petrol as possible from all my carburettors and fuel tanks before storing them away. Modern unleaded fuel contains all sorts of evil stuff deemed necessary to reduce emissions. When modern petrol is left in small carbs it evaporates off and leaves a fine white powdery residue on exposed surfaces. If this powdery residue is left for extended periods of time it crystallizes and increases in volume substantially, which can seize moving components and potentially ruin a carburettor altogether
I now treat all my petrol in the can with an inhibitor so I know that all my machines have some protection, but I still drain them off completely for winter, a lesson learned from bitter and expensive experience. If you know for certain that you will use all your petrol within 30 days you should be ok, but make sure that you do!
Regards
Bill

I use this stuff exclusively. First for my chainsaws, and then for everything else. It stores forever in the can, or in the chainsaws. I try to store chemicals like you would food or perishables, cool and dark. 5-6-7 year old fuel from forgotten 25l cans is not a problem in my Stihl's, they scream along just fine. And it's the cleanest fuel available out there. 2 and 4 stroke varieties.

https://www.aspenfuels.com/knowledge/knowledgebank/what-is-alkylate-petrol/

"Petrol is petrol, you might think. And that is not all that surprising. You pour something into the tank, pull the starter cord, and sooner or later the engine will splutter to life.

But it’s not really all that simple. There are a whole array of differences between alkylate petrol and the petrol you get at the pump at a standard petrol station. The key difference is that alkylate petrol is an extra pure fuel form. Alkylate petrol is made of gaseous hydrocarbons found in fossil fuels: these are a kind of vapour or gas that occurs when refining oil. This process is called alkylation, and involves combining excess gases from the distillation of crude oil and from the cracking plant, resulting in a liquid alkylate. Some additional components are then mixed in, resulting in the finished fuel.

This provides a fuel that is significantly purer than traditional petrol. The content of harmful aromatic hydrocarbons such as benzene and polyaromatics (PAH) is close to zero."

I moved on to alkylate some time ago for garden equipment but in UK it's a bit expensive for general use

Sattley ran ok on ten year old petrol just smelled a bit....

Woodsman wrote:I moved on to alkylate some time ago for garden equipment but in UK it's a bit expensive for general use

Agreed, here it's almost twice the price of pump petrol. What justifies it commercially is the smell and health issues in gardening, farm and forestry. I have a 100 acre parcel of forest, and switched over 15 years ago when I discovered that it was almost fumeless compared to pump petrol when I were out cutting firewood. And then I discovered that it kept forever, without settling or getting stale, so I started to use it in my vintage petrol engines too. Which I still try to remember to run dry after a start up btw.

And I also use the 2-stroke alkylate even for the 4-stroke engines, as it doesn't smoke, and I hope the extra oil in it will help to avoid pitting of the valves and seats in storage. And perhaps even corrosion in the tanks. Time will be the judge of that, and I might not live to find out. But so far a 15 year old restoration of a worn and seat-pitted and thoroughly lapped JAP 55 still retains enough compression to fire right up once every other year or so.