[Johnny Canuck]

After not riding for 3 weeks I got a break and went out yesterday in 5 degree (C) weather. While taking longer to warm up, once on the highway I couldn't help but notice a smoother running engine. My carbs are not that far out of sync to begin with (I'm assuming they are slightly out of sync due to some slight engine vibration), but yesterday the engine was bearly producing any vibrations. I did notice this same "smoothness" one other cold day, but didn't want to ask until I confirmed with another cold weather ride. So...can the cold weather affect carberation like this?

 

[InWeldingWeTrust]

Yes, cold weather can affect carburation in this mannner. Basically cold air is denser, so in a carb opening of a fixed aperture more oxygen gets packed into the charge and in effect leans the mixture somewhat. Two stroke race bikes also love cold weather and are as sharp as a nail!

 

[nolavox]

Yeah Man... Dense air, as in colder or at lower altitudes is more molecules of potential horsepower and torque going into those jugs. Add High Barometric pressure and A bit (less) of the trypical 100% Humidity in the air. It's our annual free "Tune Up" here. That Turbo boost will also have a bit more umph!



I wonder what the HP gain is between 5c and 41c on a 55hp Cx at sea level, AP-1012mb, say 10% vs 60% humidity at 9000rpm... Tuners?





here's a cheat sheet for the math inclined



http://www.small-block-chevy.com/WE.htm