Couple of carb q's for a 400ex

[Which 450?]

Since my buddy had his 400ex rebuilt, i think it is a 417 11:1 compression, a cam and some other things... It has never idled, he has the idle screw on the carb bottomed out. He has to raise it up at the thumb throttle. He has the stock pilot jet and the choke was removed. It has NEVER had a problem starting. Pump the gas 3 times, hold it half throttle and it fires right up every time no problem no matter what the temperature.

Also, when he's moving at a steady pace usually in 3rd-5th gear, the throttle will not go over 1/4 throttle unless you hit it, and it will free up for a few moments. I took the top off of the carb and looked in, it looks like the slide gets stuck all the way down and needs a little extra kick to get freed up, like suction is holding it down or something? And Ideas?

If I need any more information let me know Ill ask him.

[jordan_m6]

i noticed that also after taking my choke out. i would also like to know how to stop this.

[premiumtommy]

why do you people remove your choke?

what purpose does it serve?

its not like you gain horsepower by removing it. and dont say you do because you DONT.

and the reason for your prob might be because you improperly returned the pieces after dissmantling the carb.

put your choke back in and see if it works the way it should.....

[Which 450?]

It didnt start until a few months after the choke was removed. It was removed because under heavy loads it would close.

[Which 450?]

Originally posted by jordan_m6
i noticed that also after taking my choke out. i would also like to know how to stop this.

which did you notice, the throttle sticking or the no idle?

[ALLUWANT]

first off your choke doesnt have anything to do with your needle. if its getting stuck then its in a bind. take it back apart and re do it. if the bottom of the needle is showing any brass color then its time for a new needle and thats your prob. the air fuel screw should only be out about 3 to 3.5 turns at the most. any further than that you need to bump to the next pilot jet.

hope this helps

[jsmith2232]

I just had mine bored to a 416, 10.8:1 je piston, and hotcam stage I, k&N airbox lid and full exhaust and i am running a dynojet main 170, dynojet needle with the clip in the middle, 42 kehien pilot and screw 3.5 turns out and she runs awesome,

[underpowered]

Originally posted by premiumtommy
why do you people remove your choke?

what purpose does it serve?

its not like you gain horsepower by removing it. and dont say you do because you DONT.

and the reason for your prob might be because you improperly returned the pieces after dissmantling the carb.

put your choke back in and see if it works the way it should.....

we remove it for a few reasons:
1. Throttle response. IT gives you better throttle response off idle.
2. It actaully does give a slight power increase throughout the Rev range. it is actually a noticable gain. Figure, you are removing an obstruction from the path of the air entering the combustion chamber. it flows better than stock. It is no big improvement, but it is a pretty much Free mod.

[Chino886]

Originally posted by underpowered
we remove it for a few reasons:
1. Throttle response. IT gives you better throttle response off idle.
2. It actaully does give a slight power increase throughout the Rev range. it is actually a noticable gain. Figure, you are removing an obstruction from the path of the air entering the combustion chamber. it flows better than stock. It is no big improvement, but it is a pretty much Free mod.

I agree.....with the stock carb if you have it jetted properly, you don't need the choke, it just restricts air flow. I took mine out and it starts better now I think. If you have ever looked in there, you will see it just closes up the "diaphragm", you can achieve the same thing by putting a plastic bag over the air filter (to lessen the air, more fuel).....

[Which 450?]

Turns out it had a 40 pilot in it and was turned out 5 times. I put a 42 in it and turned it to 3.5 times out. Idled perfectly on the 1st try. The throttle... since the last time I had it apart, the slide had become really gouged, very strange, but I sanded it down 180-220-400-600, then i polished it up. Now it runs like new and I am owed a case of coors.