Jetting question

[tazman7]

I am kinda lost when it comes to jetting a quad. I am going to buy a 250r in about a week and he told me that it is jetted for 75 degree weather. Does this mean that I am going to have to change jets everytime the temp goes up and down? What exactly does jetting a quad do? So if I go out and ride it in 35-50 degree weather is it not going to run right? I like to ride hard and I dont want anything slowing me down. haha

engine is a esr 265 running race fuel

[bwamos]

Jetting has to be a bit more precise on a 2-stroke. You will have to rejet the carb for altitide and temp/humidity changes. You'll certianly have to jet differently for 40deg vs. 100deg temperature. Colder air is denser and, therefore, has more oxygen in it per cubic foot.

Here's a couple good articles for you:
Keihin Carburation Jetting (http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml)
2-stroke engine FAQ (http://www.duncanracing.com/techfaq/FAQ_2-stroke-engine.phtml)
2-Stroke Engine Maintenance Guidelines (http://www.duncanracing.com/techfaq/Tech_2-stroke-engine-maintenance-guidelines.phtml)
2-Stroke Pressure Testing (http://www.duncanracing.com/techfaq/Tech_2-stroke-pressure-testing.phtml)

[tazman7]

hey, thanks for posting that- it sure helped.

[400exstud]

Don't take this the wrong way but you may be getting in WAY over your head if you are going to get an ESR 265 and don't know what jetting does. These motors are very finiky with jetting and mods. If you don't have them right on they suck nuts and can wreck the internals of the motor.

[tazman7]

Well my grandpa is a mechanic who used to race snowmobiles professionally so im sure he will figure it out. I just wasnt sure what it was.