scoot ran faster in the winter

[vs7]

I noticed my that my scooter ran faster on very cold winter days. I guess I would like to know why..as in what mechanisms benefited from the cold. Any advice on customization options related to cooling would be greatly appreciated.
I have the standard 150cc gy6

[bandito2]

Dry cold air is more dense that warm humid air. Perhaps your bike runs a little rich in warm weather and have a more favorable fuel/air ratio going in the cooler, drier winter air giving it just a little boost to HP... (when I flew an ultralight trike in cold air it had more oomph and the wing flew better too in the relatively denser air compared to summertime flying anyway) that is if you use your bike in the more northerly areas where those conditions occur. Might also have different seasonal fuel formulations that might be making a difference. (up here in MI fuel formulations are different between summer and winter... not sure what the exact differences are, but they do occur) Or possibly a combination thereof. Just shootin in the dark, but maybe there is something to it.
:shrug2:

[Roscoe]

Here ya go, things to think about next time your riding to the store for a loaf of bread. This paper is about air cooled air craft engines but it applies to our scooters. http://www.dtic.mil/dtic/tr/fulltext/u2/a800840.pdf

[Shadowfire]

I'm going to go with the "Crap mechanical speedometer reads higher when it's cold, bike isn't actually going any faster" line of thought here.

[Irish]

On aircraft (radial engines) , we used to use an ADI mixture (anti detonate injection) It was an alcohol injection that was used on full power on take-off to cool the cylinders under a heavy load. This was on refuelers that might have a full load of refueling fuel (think JP-4) Perhaps you're getting the same effect! :hmm: Irish:scoot::nuts: