Carb problems

[deerman2701]

So my buddies quad always sputters and trys to die when u give it a good bit of throttle. but when you pull the choke all the way out it runs better and doesnt sputter. what could this be?

 

[hawkster0001]

jetting, try adjusting the needle, i can get some pics up if you dont understand, but then also try the air pilot screw

 

[deerman2701]

yea where are these on the carb? do you have to take off the carb to get to these? sorry im a noobie to this stuff

 

[hawkster0001]

heres the needle, its attahced to the slide and you will have to remove the gas tank and shroud to get at the top of the carb, where there will be three screws on the top that you have to take off.

heres the needle in the carb

heres how to adjust, you will need a small screw driver to reach down the slide and remove two screws ont he bottom of it

heres the pilot air screw, turning it out increases fuel in themixture, turning in decreases fuel in the mixture, stock setting is 2 turns out from full in

 

[hawkster0001]

and since your running better with the choke in your gonna want to make it richer, but only do one step at a time, this needle will affect alot. then you fine tune it with the air pilot screw (which is on the bottom of the carb on the front side of it, you dont need to remove any thing, you just need a short flat tip.

 

[deerman2701]

i looked on the bottom of his carb and it looks like a screws missing from the bottom or something hmmm theres a hole haha

 

[hawkster0001]

that would probably be it, its the only gold flat tip screw ont he bottom so its impossible to miss, its 12 bucks for the pilot screw set
http://www.yamahapartsnation.com/pages/parts/viewbybrand/2/Yamaha.aspx