I run my mt ins freezeing weather all the time with no probs. I did have a Tmaxx that would vapor lock on me sometimes though. The fuel line was right against the cooling head and when the engine got hot the fuel would vaporize and get locked up. Also when the engine dies does it rev up and die or bog down and die>? If it revs up that means its running out of gas and if it bogs down it is getting flooded(too cold etc.)