stale 2-cycle fuel

Sep 02, 2007 8 Replies

This is probably a dumb question, but I'm gonna ask it anyway. Will the oil in old 2-cycle engine fuel hurt the oxygen sensor or catalytic converter in my truck if I pour a gallon or two in with a full tank of gas? (That's how I got rid of it when I had an old truck w/ a carburetor and no converter.)



I assume the dilution is great enough that it won't be a problem.



BTW, don't try this with dirty paint thinner.



Bob


It has never hurt my '93 fuel-injected Dodge V8. As you say, the quantity is very small assuming that the vehicle's tank is large and close to full. If that bit of oil is going to seriously hurt anything, what about an engine that is burning a quart of its own oil every couple of thousand miles which wouldn't be at all unusual?

no.

you assume correctly.

s

i wouldnt do it if the gas is stale smelling..

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Well I would not pour 2 gallons in all at once. I have and would pour a half gallon into an almost full tank. Frankly pouring it all in at once is not likely to cause a problem but since it is both 2-cycle and old, I would do it a little more slowly.

I do it with a 1991 Mercuy Tracer, 4 cyl, FI.

I put in a half gallon of 2 cycle mix from the hedge trimmer with a full tank (12 gals.) in the car. Do that in the fall, about 2 weeks before my annual change of the fuel filter in the Mercury.

I also put left over chain saw gas ( oil mix at a 42:1 gas to oil ratio) in the car, if I have any. I cut so much wood, though, for the wood stove, that I seldom have stale, left over chain saw fuel. Do the same with the left over gas from the mower, but thats 4 cycle engine and no oil, just Stabil.

So far, (knock wood), so good.

YMMV.

Literally.

But that's it's own oil. Of course it doesnt' hurt it. It's like eating food you've sneezed on or spit on. It's your sneeze and spit, so it won't hurt you.

OK, i'm kidding.

Nope, been doing it for many years.

Hi, Good 2 cycle oil is very clean burning any way. I don't think it'll do any harm to your O2 sensor.

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