ok heres the deal... my 400ex (with pro meg full system, 8 one inch holes in the lid, and a K&N filter) it hesitates when i give it gas in neutral... it runs flawlessly when riding but when i come in from a ride (engine will be hot) and i put it in neutral and give it gas it hesitates slightly it never hesitates if the engine isnt hot.... like if i crank it up and let it idle to get to running temperature it wont hesitate but it does when i come in from a ride.... so how do i cure this.... ive been told i need to move the needle... if so where should i move it..... am i running rich or lean.... and my last question is can i cure it by adjusting the fuel mixture screw on the bottom of the carb because i know that screw controls up to 1/8th throttle well thanx any help or tips will be appreciated

 

needle is midrange isn't it?

wouldn't you need to adjust your air mixture screw..

 

yeah maybe so... does the hesitation mean im running lean or rich.... thanx man

 

Do you mean its boggin' or buckin'.
If your machine is boggin' it means your getting to much feul, jet down to decrease gas intake.

If its buckin' that means its not getting enough feul, jet up to quench your machines thurst.

Your air/feul mixture screw (I did'nt know a four stroke had them) should be set at 1 1/2 turns out from the closed position.
GOOD LUCK

2000 SCRAMBLER 400 2X4

SCRAMDADDY400

 

i know for a fact that the stock setting for the idle mixture screw is 2 and 1/4 turns from lightly seated position.... i have a jetting thing that says 3 and 1/2 turns for my mods... im not sure if it is or isnt at this setting i will check soon if it isnt at this setting do u think thats whats causing the hesitation.... my engine isnt bogging it hesitates when i give it gas in neutral then it kicks in but the hesitation is only slight but it didnt do this before

 

correction on my last post i meant to say that it was the fuel mixture not the idle mixture screw