That's an interesting question. I had a gallon of Byron's that I opened in October and didn't use again until Late April. My engine ran well but I have been through two plugs in three races. Plugs looked new but the coil had broken. I have new fuel now so we'll put this idea to the test.
Your engine does sound shot though. How is the compression?
"I have no idea what you're talking about, so here's a bunny with a pancake on it's head."
In mind and body, we're all heading towards old age. It is slower to go by bike.