Carb help..ASAP Please

[97WarriorRider]

Hey guys..Well awhile back I bought a carb of a fellow member..ever since I put the carb on it backfired about 1/4 throttle. If you start the machine and hold the throttle just off of idle it will sputter but if the choke is on it will run fine. About 20 minutes I took the carb apart and put the stock main jet in. It did have a 155 when I bought it. Also my dad thought it might be the jet needle not in the right position. So we pulled it out of my other carb that was all stock and it was on the 3rd down right where the book said it should be. So then we pulled the jet needle out of the carb im using and its on the 3rd down too..But the needles are different. The needle that came out of my other carb has 5 slots and the needle out of the carb I bought has 6 slots. but when the needles are stood up next to one another the slots are in the same position the needles are the same heighth except the needle with 5 slots is tapered and the other is flat on the tops. The only other thing different is that the 6 slotted needle( the one im using) seems to be not as round as the older needle. Should that make a big enough difference that it would make it pop like that around 1/4 throttle. Being that It runs fine with the choke on(no air) but with the choke off it acts like its not getting enough gas. But shouldnt a less diameter needle let more gas through?.....I guess im stumped and would really like some help.

[97WarriorRider]

oh..The 5 slotted needle is from a 1999 carb and I believe the 6 slotted is from a 2001 because you have to tap the float pin out. Did Honda change the jet needles between the years?

[97WarriorRider]

Guys i really need help..I know theres some on here that know carbs..I would ask on another sight but its down(no offence..I just get answers there quicker b/c the board isnt as big)..Whats the air/fuel screw..I was told that i need to adjust that and the popping would go away..I was told it was on the bottom of the carb and was gold..but the only thing I saw was the Pilot..Are they the same thing? As you can see..I know nothing about carbs..

[97WarriorRider]

Its a 42 pilot with a 148 main??yes its clean..and arent the slow and pilot jets different?? and whats the air/fuel screw?

[97WarriorRider]

Where is the air/fuel screw on the 400ex carb?

[97WarriorRider]

If the pilot is the slow jet why does the manual refer to them seperatly and show different pics? Yes I have a manual but it only says how to take them apart..Not what they do and how to adjust them..the popping is right off of idle..its before 1/4 throttle..can someone tell me where the air/fuel screw is?

[97WarriorRider]

ok. Yes the slow jet is the stock 38.....But I have been told by many that I just need to adjust the air/fuel screw..But have no damn idea where its at..thanks for the pics..the manual had them too..But that did help

[97WarriorRider]

TTT

[TRXRacer1]

The Pilot does idle to 1/8th throttle. Basically your needle and main take over from there. Did you swap a stock carb for a stock carb and why?

[97WarriorRider]

yeah I bought a used stock carb b/c my stocker needed a float, valve needle and seat which is 60 bucks..the used carb was 30

[97WarriorRider]

ok...where is the air/fuel screw??