My 2004 kodiak 400 idles fine but wont run at low throttle. I bought this used and it wouldn't run without the choke on. I thought I could fix that with no problem. I disassembled the carb and found the float was about a half inch out of adjustment, I'm surprised it would run at all. I adjusted the float, put it back together and that fixed the choke problem but now it wont hardly run at 1/8 - 1/4 throttle. After messing with it for a while I got a rebuild kit, cleaned the carb replaced all the jets and adjusted the A/F screw 2 turns out, the only thing in the kit I didn't replace was the needle set. Now it will scream at 1/2 to full throttle but spits, sputters and bogs down at low throttle, and most of the time it wont idle down. I checked the plug after a short ride and it was black like it was running rich but I've adjusted the A/F screw both directions and cant fix the problem.
Any ideas?

 

When you replaced the air fuel screw did you get the spring washer and O ring out of the hole? I have had them hang up before in there and do the same thing to me. Also hold the needle in your hand put spring washer than O ring on and hold it strait up and bring the carb down onto it because some of the rebuild kits O rings are small they want to fall off when you put them in without being upright.

 

I went back through the carb to verify everything was assembled correctly. According to the parts breakdown for that carb it is assembled correctly with all the correct jets. The only thing I didn't check was the throttle needle setting. After seeing the mess the previous owner left in the carb and seeing how black the plug was after idleing, I would like to check that setting. but cant figure out how to remove the needle. I understand how to adjust the c-clip to change the mixture but I don't know how to remove the needle set so I can get to it.
I removed the cap, and long spring pushing down on the needle / diaphragm assembly
I've got the needle/ diaphragm, throttle valve assembly out but cant get the needle out

I grabbed the plastic piece inside the valve with needle nose pliers but couldn't pull it out. I wasn't sure this was how to get it out so I didn't pull too hard,
This link is the breakdown of carb. I've got #2,4,5,6 out but cant get them apart
https://www.yamahapartshouse.com/oem...f42/carburetor
Should the needle just pull out the top of the throttle valve?

 

 

I got it running good. Ended up I think the PO put the wrong needle set in the carb. I replaced the needle set and it runs great now.
Thanks for the replies.