[mrrandyman]

Is there anyway of checking to see which component of Nitro fuel that is causing a smoke problem?
Or which component in the fuel has degraded?

Randy

[MikeCam]

Fuel goes bad if it is left open to absorb moisture from the air. Other then that it should stay fine for years. Sunlight was said to destroy Nitro in fuel but I read a model fuel company in California left out one bottle in the sun for 6 months and kept a second bottle in a dark place. Both fuels worked fine in a test engine.

[Frank Klenk]

Need more info.

[aspeed]

Yes more info, but mostly the oil is what will smoke. This could be stale fuel where most of the nitro and methanol has evaporated out. This will leave more oil than normal. It could also be water absorbed in the fuel. Overheating will cause smoke too.

[mrrandyman]

I'm not really sure what to add to my inquery but do appreciate the comments. The fuel is Omega 15 and is from last season. It has been stored in a cool dry area but when it was being used it was during our very hot summer.
I used it for the first time this season at the annual spring float fly in a Used saito 82 and had one of our Club engine experts set the engine up for me. The engine runs great but it sure smoked pretty good and was told the fuel had probably deteriorated some.
I think my major mistake was emptying my tank back into the jug after my flights.
I was not aware that doing so would add moisture back into the jug and damage the fuel.
( Now I know )
My interest in the mean time is or was wether a person could figure out how much nitro or methanol to add back into the jug to freshen it up while still maintaining a usable mixture that would not destroy the engine.

[aspeed]

Unless there is a lot of moisture in it, and it doesn't run, or idle right, I would just use it up quick. I have often found the second or third season of opened fuel doesn't always work good. Maybe use an after run oil to protect the bearings in case there is some water in it, the nitro is high enough to cause rust too. I don't think too much oil will hurt it. If the smoke is definitely white it may be water vapour, but a blueish tint is likely oil.

[moo]

Originally Posted by mrrandyman

figure out how much nitro or methanol to add back into the jug to freshen it up while still maintaining a usable mixture that would not destroy the engine.

Nope, you have to remove the water, not change the proportions in any other way.

Is your smoke steam from the water in the fuel?
If you are using synthetic oil in the fuel there shouldn't be any smoke from it, the smoke point of that oil is probably close to the burning point of the engine gaskets and o-rings.

Cloudy fuel can indicate water too.

Does the engine smoke if you richen the mixture? (slightly)

[mrrandyman]

The smoke is white. I only really see it when it is in the air. It shows no visible sign of smoke on the ground, Only a fair bit of oil. I ran it in my 2 stroke today and again did not notice any real smoke, just a lot of oil from running it rich. It is a new engine.
Taking another look at the jug this morning I could see what looked to be a little condensation on the inside of the bottle.
Too bad there isn't a dryer product you could use to obsorb the moisture.

[Flyinbullmax]

I was wondering, if we put a bottle of gas line conditionner to absorb moisture in the car during winter, I guess it would do the same in a jug of nitro. And its alcohol too. What you guys think?

[Skidoo55]

Interesting discussion here. If it was me, and your motors are running okay on it, I would keep running it as it is... At the most, you have 4 litres of it. If it concerns you so much, buy a new jug, and don't run anymore of the old stuff.

I wouldn't experiment with adding other products to the fuel...You may do more damage then good.

In the snowmobile world, there is a product that we can place inside the gas tank on the sled, and it absorbs and captures the water in the fuel. However, water and gas don't mix, so it's a different scenario. The fact that you can see moisture on the side of the jug indicates that the water can come back out of solution, so what would happen if you hung a packet of silicate from the closed cap, but not touching the fuel. Hmm, could work!