Yea lets make this jetting 101. Im panicing because i gotta pick a jet for my 05' trail blazer. AAEN wants to offer me 140,145 and 150. And i got no clue y i need 3. I live in NY. Do i gotta like change it every season or sumthing? And which one do i install now? its spring

 

Theres a main jet and 2 other jets(piolet jets). You dont need to change them unless you get a pipe or filter that recuires the jetting. Jets are inside the carb. they are basicly little needles that you mixture goes through.

 

I believe thats it!?!?!

 

what altitude are you at wher do you ride?? 0feet - 3000' should be able to use the STOCK jet it may be a bit rich if it is a new machine as the factory do that so the motor gets more lubrication when it is new. I ride between 0feet and 4000 feet and in the 300 hawkeye i have a 140. main jet and stock pilots anad in my sportsman 500 i left the stock one as it runs good. Also jets(main ) will (could) limit top speed if you were to go to low. They arnt that hard to change i would try the factory one recomened and go from there. The jets are pretty easy to change.

Trailblazzers@shaw.ca erik

 

All manufactuers have a jetting chart for every machine it show temps and elevation for riding most of the time they are on the conservative side though. When you go to any aftermarket part the aftermarket company should know exacttly what jet or jets you should need. On your particular machine the 250 trail blazer it come stk with a 130 which polaris considrs safe for 0-3000" in elevation and a temp range of 40-80 degrees. See chart bellow

altittude bellow 0 0-40 40-80 80+
0-3000 150 140 130 120
3000-6000 140 130 120 110
6000-9000' 125 120 110 100
9000-12000 115 110 100 95

If aaen suggest 2 sizes richer you cna jsut add 2 sizes to this chart and you should be pretty close. Hop ethius helps clear up any confusion you are having.