Fuel additives for outboards

[Storyline]

Have seen the recommendation to use bp premium petrol but does anyone think that there are any additives that are worth using with a small 2 stroke outboard ?

 

[Lakesailor]

Nope. They'll dilute the calorific value of the fuel and just be something else to gum up the carb.

 

[Storyline]

Thanks, that is one less expense.

 

[Trundlebug]

The only additive worth using is one that prolongs the life of the fuel if you don't get through very much.
Modern petrol appears to have a shorter life than in the days of good ol' 4 star, and it turns to jelly and gums up carbs etc leading to rough running and poor starting when using old fuel.

I bought mine from Frost, (OK it was a few years ago) but have just checked for a link and they seem to have stopped selling it.
The nearest I can find is this http://www.briggsandstratton.com/us/en/shop/why-genuine-parts/fuel-treatment
Clearly designed for a similar usage environment as many outboards.

As regards octane boosters and any other fuel additives that supposedly give you extra power, efficiency, life, smell, nice noise or anything else, don't bother.

 

[ip485]

My personal experience is that if left for more than a few months my outboard failed to start without the additive - started third or fourth pull with it.

Of course you could just make a point of always running the carb dry - but sometimes I forget.

 

[michael_w]

It made a huge difference when in the US because of the ethanol. Now we are being subject to the same "green" measure I have started adding a stabilizing additive.

 

[VicS]

Fresh fuel is the real answer with today's gasoline blends . Ethanol is probably the biggest cause of problems and they will get worse if/when the % is increased.

Fuel stabilizers seem to be very popular with outboard users in the USA. Sta-Bil products are often suggested but I am not sure if they are readily available in the UK.

http://www.goldeagle.com/brands/sta-bil

 

[Trundlebug]

Fresh fuel is the real answer with today's gasoline blends .

http://www.goldeagle.com/brands/sta-bil

I agree Vic, but there are applications like outboards and lawnmowers where the usage isn't sufficient (quantity or frequency) to ensure fresh fuel is always used.
Especially as many garages have a minimum charge / volume these days.
In such circumstances it creates another problem, what to do with the remaining, unusable, old petrol?
Disposal at the local tip with waste oil is quite easy but really hurts given the price of fuel these days. And it just doesn't feel right!

Far better to try and prolong the fuel life and enable it all to be used up.

 

[lw395]

2 stroke oil?

 

[Storyline]

How much of the petrol evaporates ? Have always assumed nearly all of it so have been known to dump it on piles of rubble etc.

 

[lw395]

How much of the petrol evaporates ? Have always assumed nearly all of it so have been known to dump it on piles of rubble etc.

There are additives in it which might not evaporate.
But the ethanol absorbs water from the air, that seems to react with the additives to leave a residue.
The 2T oil won't evaporate.

 

[VicS]

, what to do with the remaining, unusable, old petrol?
Disposal at the local tip with waste oil is quite easy

You may be lucky but ITYWF that generally disposal of old petrol, diesel and even old cooking oil in the waste oil tank is not allowed. Certainly not at our local one.

Its not a problem though I put it in the car! Which reminds me i will have about 4 gallons, minus a little that the mower will use, to stick in the car tank soon.