Small Engines (Lawn Mowers, etc.): Premix oil shelf life, stroke oil, quart bottle

Question
How long will 2-stroke oil last sealed in it's original quart bottle?  I mean not mixed.  I have an old case from 1990.  It seems to be OK but my plug is fouling in 1987 CR250.  Problem may be unrelated to age of oil?

Steve

Answer
STEVE,
I JUST DON'T KNOW THE GOOD ANSWER TO YOUR QUESTION.  IF IT
WERE ME, I WOULD CONTACT THE MANUFACTURER OF THE OIL AND RE-ASK THE QUESTION.  I FEEL AS THOUGH THE OIL WILL HAVE DEGRADED SOMEWHAT BUT I AM NOT SURE.  I WOULD NOT USE IT TILL I TALKED TO THEM.
I HOPE I HAVE STEERED YOU STRAIGHT ON THIS ONE.

GEORGE