why would a qaud run better when the air starts to cool down .......... i know cooler air is better to mix the fuel and so forth... thats why drag cars run cool can filled with ice with there fuel lines running thru the ice.......back to the qaud.. its not starting to run lean is it? its a 2 stroke 400 its a buddies or is it the cooler air... right about dusk maybe 4 degrees cooler... hope this post makes sense

 

I know what you are talkin about and i am wondering the same thing lol Mine always seems to pull a little harder in the cold

 

When air is cold it is more dense. Therefore you get more oxygen which is used to combust the fuel. So the more oxygen you get the faster the gas combusts per stroke, the more power you get and the better the machine runs. But once the machine itself totally heats up the air heats up around the bike relatively quickly.

 

sooooooooo i guess its not leaning out then to much huh. i get what you saying....

 

No not exactly leaning out...basically what is happening is it leaning slightly to give u a boost, the air molecules cool the cylinder and it requires more force. So it compensates by using more fuel. It just refills faster and inturn increases out put. Im guessing this power goes away after about 10 minutes of riding right?

 

no not really... its more crisp the whole time we are riding never really goes away... we were already riding for about a hour....noticed the more response in throttle... then about half hour till it got to dark..... i was think on warm to hot days if jettting down a half jet would do the same thing probaly not huh.... cause the outside air still warm to hot.......

 

I dont know how much changing the jetting would do. The main needle would help mid range more. When I had my 2 stroke it just seemed to ride better for a few minutes. Here's a little experiment for you... Try riding for 10 minutes with the airbox cover off. Unless u have a K&N stay away from water for these 10 minz. You should definately notice a difference in the power. This is because of the increased air flow. The same basic idea is happening in cold weather. Its not as obvious on my bike because it is sluggish due to the 560 lbs. it hauls ne ways. But If you have more flow mixed with proper jetting you could probably increase your overall horsepower by 2-4.

 

Be careful running with the airbox lid off. If you get too much air and you are not jetted for it, you will be too lean and may seize your motor. If you are running better in cooler weather then you may be slightly rich, but air density increases your mixture, so you may be where you need to be. The only real way to know is to check your plug and jet accordingly. If you do remove the airbox lid and it runs better, then you are too rich, but like I said, be careful with that because you can burn the motor up quick that way, plug reading is the preferred method.

 

Please don't go running around with your airbox lid off. An air filter is on your machine for a reason....to clean the air. Cold air has more oxygen, denser, it's leaning out your machine. You can always do a ignition chop, jetting check. Dirt is bad, HP is good. Jet your machine right, and you'll have the HP, and machine longevity. [img]i/expressions/face-icon-small-happy.gif[/img]

 

yeh i know mod ........... just asking ............... i already removed my airbox alredy jetted for it