crf 450 carb tuning 2003

[ollacolla13]

having problem tuning my carb... yes i have read the manual.. the jets are right, valves are good.. still having trouble starting... needl is third from the bottom and pilot air screw is 1 3/4 turns out... and don't know about the air screw but it was turned way out... thats how i tuned it to low down the idle when i got it started... will start fine when its hot... in the manual it says 5th position for the needle and idk if its from the top or bottom... please help a little thanks

[fxrs]

are you using full choke and 3 twist of throttle

[tjg53]

Your poilt jet mite be getting clogged. Try a new one , and see how it acts. Over time they do get clogged with varnish.

[450XJimDirt]

I am gonna agree with tjg53 , your pilot jet is clogged , thank the Ethanol for that

If you have the proper jets for your altitude , and you read the manual and set everything to the recommended settings , then its either old/bad gas , or your pilot jet is clogged

[ollacolla13]

in the manual it says for the needle position to be on the 5th spot... does it meet the 5th position from the bottom or top?

[fxrs]

i would say from the top because it richens fuel you move the clip down

[skthom2320]

Needle clip position is counted top down. +1 on the recommendation to just switch out the pilot. That is a classic symptom for a clogged pilot (or fuel screw too far in).

BTW - there is no air screw. The fuel screw on a FCR carb is letting in more or less fuel in the pilot circuit , not air.

[ollacolla13]

my bad i meant fuel screw... i'll try a new pilot and see whats going on with that...