Fuel additive

OceanSprint

OceanSprint

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I run a 4 stroke 9.9 yamaha outboard on unleaded. I dont use much fuel, so fuel in 25L tank can get quite old, and weeks can pass bwtween engine runs.

Local service engineer recommended Quicksilver QUICKSTOR Fuel Stabiliser should be added to the fuel. Is this correct? Thanks.
 
If it makes you feel happier. I'm not convinced fuel degrades in a few weeks/months. My garden equipment sits all winter with fuel in it and starts happily next spring.
 
OceanSprint said:
I run a 4 stroke 9.9 yamaha outboard on unleaded. I dont use much fuel, so fuel in 25L tank can get quite old, and weeks can pass bwtween engine runs.

Local service engineer recommended Quicksilver QUICKSTOR Fuel Stabiliser should be added to the fuel. Is this correct? Thanks.
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Excellent choice. I've done considerable fuel additive testing for a pesky US magazine (Practical Sailor), and Merc is one of the few that really stops corrosion. B&S and Biobor EB are also very good. Most are not. The pitty is that there are zero standards regulating what they can sell. I wish ABYC would fund the research.

The difference with most garden equipment is that the carbuerators are NOT designed the same. Instead of an free surface in a bowl, there is a diaphragm. otherwise, they would spill and burn if tipped over.

The greatest challenge to gasoline is the E10 (ethanol gas--we've had more of it and for much longer due to a powerful farm lobby--ethanol-free gas is now virtually extinct) absorbs water, this triggers corrosion, and the aluminum bowl with dissimilar metals (aluminum + brass) is a perfect environment. then 2 things happen. The aluminum corrosion products (fluffy bloom) clog the jets and the dissolved ions polymerize the gas.

As an experiment, take 2 jars, put a little e10 in each with a few drops of water, and put a few pennies in one. The gas will turn.
 
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OceanSprint said:
I run a 4 stroke 9.9 yamaha outboard on unleaded. I dont use much fuel, so fuel in 25L tank can get quite old, and weeks can pass bwtween engine runs.

Local service engineer recommended Quicksilver QUICKSTOR Fuel Stabiliser should be added to the fuel. Is this correct? Thanks.
Click to expand...

It could be wise if you are storing petrol for many weeks

It is probably more important with petrol containing ethanol than it was in pre-ethanol days and if/when the ethanol content is increased it will become more important.

Some engines seen to be more susceptible to the effects of stale fuel than others.

When I store fuel for any length of time I do so only in tightly capped metal cans. The object being to minimise contact with air and loss of more volatile components. Having said that my main outboard tank is a 22 litre plastic tank!
25 litres is a big tank for a 9.9 4 stroke, esp if you dont use much fuel. Surely bigger than the standard tank for the engine?. Perhaps you should consider a smaller tank ?
If I was starting over again I would have two smaller tanks rather than 1 big tank, and only use one for pottering about but fill both if/when I was likely to need more.

Sta-Bil seems to be very popular among outboard users in the USA. http://sta-bil.co.uk/shop/
 
I forgot to add that for chain saws, the farm generator (and the outboard, cough, cough :) ) I use premium petrol at roughly 10p/gallon extra. It seems to start better, and be less 'greasy' when it gets on your hands by accident.

TW - do you have two grades of gasoline in the States or just one ?
 
thinwater said:
The difference with most garden equipment is that the carbuerators are NOT designed the same. Instead of an free surface in a bowl, there is a diaphragm. otherwise, they would spill and burn if tipped over.
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The carbs in my garden tractors are conventional, and I still have no problems with old petrol. Anyway, the tractors aren't easy to tip over!
 
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