Does two stroke oil go bad?

(2011-08-17 14:20:09)

1. Harvey Mushman Says: I have some two stroke lawn equipment. To save money and time, I bought a one quart bottle of Poulan two cycle oil. That bottle has lasted a few years.

A few weeks ago, my weedeater stalled, and hasn't started since. I've gone through the whole thing, replaced some dry rotted fuel hoses, spark plug, cleaned the air filter, and even fresh premix, with the above mentioned two stroke oil. I don't have the gauge to do a compression test, but it does blow my thumb off the spark plug hole. The muffler isn't fouled. It just refuses to run.

Now I would just throw it away, and buy a new one (what any good American should be doing) but my leafblower is doing the same thing now.

The only common denominator is the premix.

So what, did the oil absorb enough water to suppress ignition? Can you tell I'm shooting in the dark?

2. Paul Says: I don't believe it does. I have some older than THAT that I still use and have seen no difference in engine running.

There's not much at all that can spoil in oil. Maybe you could shake the bottle just in case there are certain components added to 2 cycle oil that settle, but as far as lubrication goes, no problem.

Now automobile motor oil has additives that will settle to the bottom of the bottle after a while.

3. k bellard Says: The castor/bean oils will go bad(once opend it is good to keep them refrigerated too prolong the shelf life)....but most guys dont keep a liter that long...
Synthetics and petroleum based oils will be ok.

yea, caster oils are the only oils that wil go bad. that being said, it still takes a good long time. for it to go bad.