Never run more than 70% concentration of antifreeze- - - -it needs at least 30% water to transfer heat properly, and pure Ethylene Glycol starts to freeze at +19 degrees F. A 50/50 mix freezes at -37 degrees F. and boils without pressure applied at about 220 degrees. If it gets colder (or hotter) than that in Tennessee, I'm moving to Tahiti!

You might be experiencing "hot soak" where the fuel in the float bowl boils and percolates into the intake, causing a flooded condition. Try holding the throttle wide open and cranking until the engine starts to clear the flood.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!