carb toubles?

[m0t0xk1d]

i have a 300ex but it has a highly modded engine with a 400EX carb so i figured you guys would know more them me. ok so at the track i hit a jump and then the throttle wouldnt go past 1/4 throttle i had to like break it free and it kept doing this on and off

also when i went over whoops it bogged sometimes ? what cuases this and how do i change it?

also when i adj. the idle it will adjust and sometimes it just goes to a really low idle and when you give it gas it dies. this is only sometimes tho sometimes it idles fien how do i fix this>?

[m0t0xk1d]

ttt

[bigd's ex]

The screws that hold the linkage to the slide inside of your carb may be loose. Same thing happened to me after I ajusted the needle & must not have got them tight enough, because 1 came loose & the other came all the way out, causing the same symptoms your're having. Good luck.

[Snipe]

Could be jetted wrong, could be starving of oxygen and could be carb isnt seated all the way on the boot or the motor. Just work your way through them. I was having kinda same problem took the airbox lid off ran fine.

Also since you hit a jump it could had knocked something loose and has gotten dirt in the carb might be worth taking apart to check it out and clean if need be.

[m0t0xk1d]

i took it all apart everything looked perfect which is th ewierd thing i will check the thing you said bigd ex im running a 170 main with uni and lid off and ported and polished and a very well built up motor and the plug comes out perfect nice tanish brown

[tri5ron]

The "I had to break it free" part, bothers me some.

Is to possible that something cold have come loose, or broke, inside the thumb throttle housing ?
maybe a frayed cable?

does the throttle plate/slide move freely with the throttle cable removed?

does the cable slide freely through the cable housing when it is removed from the carb?

did the nut inside the throttle housing come loose?

just a thought.

[m0t0xk1d]

the i had to break it free part i ment like it would go back to the position where theres no throttle but when i went to give it gas it woouldnt go past 1/4 throttle so i really had to hit it hard for it to go past that and it kept happening repeatedly. the weird thing is when i got the quad it didnt run so i tottally rebuilt the carb(literally took everythig apart) and i race it at mx 338 and it was perfectly fine. i recently just totally built the engine up and the first time out at the track thishappened. we took the carb off at the track and see if anything was hitting or binding and the throttle cover and nothing was. if this helps it only happened when it was running. it would d it if it wasnt running