2006 CRF450 carb issues

Hey guys,

I just picked up a 2006 crf450. Since I bought it it was having carb issues. I took off the carb and gave it a good cleaning. Now I'm finding that the idle doesn't sound right. So I tried adjusting the idle screw but the idle seems to hang for a second or so. I went to take another look today and while it was running and idling sorta, I turned off the gas and blipped the throttle and the idle went high. Does anyone know what's causing this. Any help or ideas would help.


You gotta clear the passage above the pilot with fishing line and spray cleaner


If you want it to run right, do both of these




..upgrade the apump linkage and diaphragm





... .. then fine tune it...



I had the bike in the shop. They did a carb cleaning. I phoned the shop and said to turn in the air fuel mixture screw a quarter turn in. Will try that later today.

We'll I took it to the shop last week and had the mechanic look at it again. He played around with the air fuel screw. Then he adjusted it a quarter turn out. I went out today and bike runs fine but has a really weak idle and will stall.

I noticed today that I turned off the gas and it idles perfectly and starts up no problem with the gas turned off.. Could it be flooding. Soon as I turn the gas back on it just starts to bog down and have a crappy idle and stall.

Any ideas?

Float level may be set too high or the float/needle/needle seat may not be able to properly maintain the correct height. I don't know all the specifics of your shop visit but if they serviced your carb they should have set the float height & verified the ability to maintain the proper level.

Ok, I got a new carb rebuild kit ordered. So I'm gonna take off the carb and clean and install new gaskets and parts properly. See what happens. This honda is really pissing me off!

Well. I took the carb out and rebuilt the carb with a rebuild kit. Started up 2nd kick and set the idle. Now idles like new

right on vicktem its nice to get it first try or two

fool with that fuel screw don't settle for stock- remote r&d screw is the way to go

right on vicktem its nice to get it first try or two

fool with that fuel screw don't settle for stock- remote r&d screw is the way to go

I agree R&D racing Float and Screw is the hot ticket.

Got another question. Now when I start the bike from cold. I pull out the choke and it doesn't want to fire up. When I don't use the choke it's starts within 2-3 kicks. Is this cause of the warm weather or my carb needs adjusting?


your pilot may be to big- what size pilot are you using now?

possibly your float is not set right?

 its rich if your starting without the choke

maybe it's just the mechanic? lol

have you taken the time to adjust your fuel screw? if not its hard to help you, don't say stock say ware it works best

I'm running 42 and a 168! I have the needle on the 4th clip. I have the fuel screw turned out 1.5 turns out. I haven't taken out the bike yet. Stock fuel mixture setting is 1.75 turn out, maybe this could be the problem?

Edited by Vick-KTM

42 should not be to rich  what about float setting? and hows the tip of the float needle?

did you get the letters off the needle when you had it apart?

11/2 is not a problem- its all about the best  setting so if you were out past 21/2 I would say put in a 45 pilot and if you were less than a turn on the pilot screw i's say put in a 40 pilot

read over real well what Kah Ran Nee posted above

Is it a real big deal if I don't use the choke anyways?

I will have to check the letters off the needle when I get home

You should need some level of choke most of the time when cold,  on a CRF.

42 should not be to rich what about float setting? and hows the tip of the float needle?

I replaced the float needle but didn't check if it was correct setting.

The letters on the needle say NCYR.

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