i have a 02 polaris sportsman 700 twin i put a k&n air filter and pure polaris exhaust and now i can't get it to run right the guys at polaris said i need to adjust my air flow screw (the one that you have to drill the brass cap off the bottom side of carb.) does anyone know what the preset on it is and any idea how many turn and witch way i need to go i think i have to screw it in??!!...

 

Did you increase main jet size? If drilling out plug ,be careful,use small bit dont drill too deep or can damage fuel/air screw,then use a screw in plug and pull out. COUNT number of turns clockwise till lightly seats,make adjustments from there. For instance if set a 2 turns,try 2 1/2. May need more adjustment. Note that the fuel air screw MAINLY controls IDLE, jetting,needle position IMPORTANT also! RULE OF THUMB on rejetting is about 20 percent increase on main jet,DEPENDING on exhaust flow and air charge increase. Sometimes may not have to rejet,just raise needle position,fuel air adjustment. NOT an EXACT science,have to play with it. Always check plug to be sure not too lean!

 

I bought a new carb from polaris to rule out everything!!!! I've tried everything move the needle to every position it has, turned the air flow screw both directions in 1/4 increments went down in main jet sizes to a 160 and a 150 and a 162.5 it is flooding out gas comming out the nipple on bottom of flot bowl it idles fine but as soon as you touch the gas it dies out clean the gas tank and fuel pump! what is left??

 

What elevation are you at? 0 to 6000 ft should be a 155 main jet although you could go down to a 152.5 at 3000 ft to 6000 ft.

 

is the float set correctly?

 

i don't know the exact elevation south carolina but polaris said i have to use a 162.5.. i shipped the new carb. back to polaris and they checked everything out and said the carb was good float height ect.....

 

As far as the idle mixture, I would start at 1 3/4 turns out. 162 main seems to be to big. My 03 700 stock is 1 155 main, you could go up to a 157.5 with your mods and try that. Also have you done a compression test on it?

 

OK i think i might have another problem other than the carb...... whac ya'll think about timing i know that it is set right (crank on the first bump of switch idle etc...) but what advances the timing when you give it gas can it be off or go bad??? (remember it runs perfect at idle but when you give it gas it dies out bad spits sputters pops.) any suggestions on that??????

 

check the carb boot between the carb and the motor. These things are notorious for cracking on the bottom side where you cant see it.

 

From service manual - Engine idles but will not rev up

Spark plug fouled/weak spark
Broken throttle cable
Obstruction in air intake
Air box removed ( reinstall all intake components )
Incorrect or restricted car jetting
ETC switch limiting speed
Reverse speed limiter limiting speed
Caruretor vacuum slide sticking/diaphragm damaged
Incorrect ignition timing
Restricted exhaust system