will cold weather affect my top speed notice a 4mph differance in top speed now that it's 20degrees colder

 

maybe...
your in dunmore huh? cool. im like a half hour from there.

 

I have noticed mine backfires alot in cold weather.

 

The reason it is running slower is because it is running leaner because of the cold weather. When the weather gets cold, the air molecules move together. This makes the engine run leaner. Rejet to a 1 size richer main jet and probably a 1 size richer pilot jet and the problem will go away.

 

I know my Xplorers would go like a bat out of heel when the temps got to about 30 below but that is flirting with meltdown. I normally rejet about 10 bigger for the cold weather (stock 310 use 320 for colder temps) If you are running a four stroke you will be fine. Try adding some gas line anti freeze. See the other topic, cold weather.

 

It will run lean because theirs like no humidity in the air when it's cold (below 32*), humidity thickens air.

 

mojave300ex

Cold has nothing to do with humidity. It can be -40 and 90% humidity. Take a look at the temps and humidity here right now.My Temps

 

my 4-wheeler goes much faster in the cold

~jenny

 

it's a 500 scr its 4 mph slower the plug is light tan with the chop test the air box is modded with six uni vents i'll try plugging the six holes giving me a more gas less air resulting in richer mixture should increase my top speed back to original speed that is if it's lean what? about clutch weights lighter or heavier for cold weather