Air screw adjustment

[ukracer]

I have 03 yz 125 and been told to run stock jetting but it still seemed to be running rich with lots of black goo from pv overflow pipe. I checked the airscrew and it was 1 turn out the manual says for here in europe it should be 1 1/2 turns out which i have done but not had chance to try yet. Will this improve or make worse?

 

[joereitman]

Turning it out gives more air, leaning it, and helping

 

[a454elk]

It may help but it still sounds too rich for the air screw adjustment to fix. You may need to drop one size on the main jet, they usually run rich from the get go.

 

[joereitman]

If you are WOT all the time the main jet change will help. If you are putting around in the woods, you may need to go one leaner on the pilot, and maybe drop the needle (raise the clip) a notch, and even go one step hotter on the spark plug if fouling is an issue. This is something you need to do carefully, one step at a time. See the carb tuning section in how2ride.com and also do a search here on jetting. It will keep you busy for hours. :)

 

[cr250john]

Click HERE for a nice article by Eric Gorr on Carburetor Tuning.

Click HERE for an article by Canadian Dave on Carburetor tuning.

Lots of good information there.
Good Luck!

 

[ukracer]

thanks for the good advice !

 

[81yzinger]

I have 03 yz 125 and been told to run stock jetting but it still seemed to be running rich with lots of black goo from pv overflow pipe. I checked the airscrew and it was 1 turn out the manual says for here in europe it should be 1 1/2 turns out which i have done but not had chance to try yet. Will this improve or make worse?

On my 81 yz 250, Sitting on the bike, which side is my air screw on? l or r ? I think idle on the left air screw on right, am i correct?

 

[Yz125Rider13]

Which side is your Carbuerator on? Hint Hint

Later :flame:

 

[81yzinger]

Im kinda new here just need help not jokes! Thanx