300ex air/fuel problems HELP!

[jpontius05]

alright, i'm thoroughly confused on this one. I've read up on jetting and feel like i have a pretty fair grasp on the concepts, but i haven't messed around w/ my quad yet, because i don't want to do anything until i know for sure what i should change.

okay, initially, i could rev the bike (300ex) up to wide-open SLOWLY, and it would reach the top end. But if i would punch half throttle, it would stutter and die. Then, once the engine warmed up, i could punch half throttle, and it would stutter but then rev up.

I drilled two holes in my airbox to see if better airflow would help. But instead it's even worse. Once it was started, it wouldn't go above idle. it owuld just die. And i could actually feel it pushing air OUT of the hole in the airbox lid. When i covered the holes up, it did the normal thing that i talked about earlier.

what does it sound like i need to do? i'm a roast. baste me.

[Cole Trane]

Your running too lean, you need to go up on your main jet.

[Fuchs42]

You are running lean (too much air) try going with a bigger jet stock for a 300ex is 124 im pretty sure try a 128 or a 130... Also then you could run it with more air (more holes/lid removed/ whatever) Basically a good upgrade for a 300ex is a 400ex carb but its a pain to get it dialed in.

[beak7707]

Did you change your jetting when you put on the pipe and filter. If not you defiantly need to increase your main jet size. If it idles fine you don't need to mess with your pilot or air screw.

[jpontius05]

I'm gonna try a 130 main tomorrow. The quad is new to me, so i didn't put on the pipe or filter. This is also my first quad, so i got a clymer manual, and i'm on my way to figuring it out. Then i plan on upgrading to a 400ex. anyways, thanx guys.
-jesse