Shitty old fuel

chrisk

chrisk

Hero member
Location
Brisbane, Australia
I have a Yamaha WR400 dirt bike which is fired up every now and then .... riding it the other day, I turned to see my opponent (read; mate behind me) only to be hardly able to see him through the plumes of blue smoke  :o

He had fuelled both bikes from a 20Lt drum before we took off. His KTM and the Yammy were both blowing blue. He mentioned that it was a can of fuel he had sitting around in the shed for eons >:(

Question is, why, if this fuel is spent, would it make the gases run blue?
I've never seen this before. 

 
Chris, modern automotive "gasolines" vary enormously in formulation in different countries and at different times of year, but one thing they all seem to have in common is that there are added volatile components that are used to increase the fluidity of the mixture, aid in upper cylinder lubrication, and assist in measuring the amount dispensed by pumps. These volatile compounds can be as simple as small hydrocarbons, things like toluene or low molecular weight alcohols or ethers, or they can be more complex. But what many of them have in common is that they are highly volatile, and that's why modern fuels really can't be stored for more than a month or so unless you use a fuel stabiliser. Which may or may not actually stabilise the fuel, you have no way to tell.
But old petrol is low in the volatile fractions because they evaporate, so the ratio of heavy oily molecules to light solvent-like molecules shifts in favour of the oily fractions. Just like adding oil to petrol. So you get similar combustion characteristics to 2 stroke fuel, lots of blue smoke, fouled plugs etc.

Ken
 
Well I took your advice and put my old fuel in the mower.  What shall I do with the remains of my old burnt out shed and electric mower now?
 
I use the last two years Aspen Plus.
It?s a high octane (98 RON) alkylate petrol what also is used for lawn mowers becaused of the less poisened substance in it such as Toluene and Benzene.
These are Polycyclic Aromates and cause cancer.  You can imagine that if you are a worker in the forest for 8 hours a day it?s very bad for your health when you smell these fuels every day. That?s the reason Aspen developed it.

Another interesting aspect especially for us is when you don?t use your bike much. It has almost no residue.
Traditional petrol gives always gumming in the carbs after a certain time. This is because they mix the heavy botom products from the destillate column with the lighter fractions.
Aspen uses only the top gasoline products from the column. It?s more pure with other words.  And there is also less fouling from the plugs (less sooting).

The only downside it?s almost 3 Euro a litre, so very expensive. But last winter after a 5 months waiting in the garage for the good weather one press on the button will start the engine in two seconds without draining the carbs before. So that?s for me the reason I use it.

Take a look at the Aspes site and you know everything about Alkylate Petrol http://www.aspen.se/Aspen/Templates/GuidePrint.aspx?DXNI=172380

Ren?
 
veravista said:
Well I took your advice and put my old fuel in the mower.  What shall I do with the remains of my old burnt out shed and electric mower now?
Click to expand...

Are you trying out for DOTY? BTW re the burnt out shed and mower, that should buff out OK....
 
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