idleing too fast

[ny300exrider]

i just rejetted my 400 with a filter and hmf slip on from a 175 w/o lid which was too rich, to a 155 with lid on. it seems to be running ok except the idle is very high. is there a screw or something that can make it idle slower without opening up the carb again? would the air/fuel screw work?

[ny300exrider]

oh yea and i guess i may have messed up because i only changed the main, and left the needle at the settings i had before. the settings i had before are what hmf recomended on their website. im thinking since i didnt change my air/fuel screw from the 175 to 155 i might have to mess with it?

[300exOH]

The idle should be a large chrome screw beside your carb that is mounted on a small bracket

[ny300exrider]

ok thanks, about how many turns should it take before it starts to work because i turned it alot and the slightest hint of it slowing down occured. would turning the air fuel screw in help this out?

[300exOH]

I usually have only had to turn mine about 1/4 turn or so. :confused:

[ny300exrider]

is there any way the the air/fuel mixture screw could make the idle higher??..... and i turned the idle screw alot and nothing happened

[ny300exrider]

ok, my air/fuel screw is set at 2.5 turns out. this is what i ran with the 175 that hmf recomended. now that i went down to the 155, should i turn the screw in? would this be the problem as to why its idling so high?

[buddy what not]

do u think since that u had the carb off u didnt get it quite back on right and its suckin air on the intake ? if it idles high this could be the problem

[plkmonster2]

Yup, check for air leaks, and also, make sure that you have slop in the thumb throttle. Once, I didn't screw the throttle linkage into the carb enough, so the cable was tight, so it acted like a high idle.

[ny300exrider]

those could definitly be possibilites, i took the carb off and will recheck everytihng and make sure to get everytihng on tight.
thanks a ton

[ny300exrider]

before i reinstall my carb again i want to know if the air/fuel screw could be the reason its idleing high. would having it screwed out too far do that? i just want to know if its even a possibility before i close up the carb again. i had the screw 2.5 turns out with my 175 but didnt change the settings when going down to the 155. if it wouldnt change the idle then i am going to reinstall and make sure there are no air leaks. plkmonster, i dont have the carb here to look at right now but can you tell me what the throttle linkage looks like and how i can tell if it is wrong? is it the cable connecting from the carb to the front of the quad keeping the carb from moving much when all unbolted

[ny300exrider]

bump, im going to try putting it on again right now making sure its all airtight and if its still high would the air fuel screw being out too far be sometihng to look for?

EDIT: just put on the carb again and made sure i tightened the two intake tubes onto it tight and the idle is still high. should the idle screw be in or out because im trying to mess with that but it isnt doing much. should i try screwing the air/fuel screw in alittle? what else would make the quad idle high just by changing the main jet

[cals400ex]

i am wondering if when you took the carb off the cable twisted a bit. this will make your throttle lever be pushed in a little bit all the time. adjust the slack in your throttle lever. i say around 1/4 inch is more than enough. more than that and you may hurt performance.

[ny300exrider]

cal and plk, i cant thank you enough. after taking my carb off 3 times for no reason it ended up being my throttle cable was too tight causing it to give it gas. ahhh

[cals400ex]

Originally posted by ny300exrider
cal and plk, i cant thank you enough. after taking my carb off 3 times for no reason it ended up being my throttle cable was too tight causing it to give it gas. ahhh


just as i suspected. ;)

glad you got it fixed. also, the idle adjustment knob should work fine now too.