Fuel and air adjustment screws?

[Nathaniel Max]

I have a 2005 yz125 and I messed up the idle screws. I have a making carb and i just want to know what the base idle is for the fuel and air adjustments. I run 35/1 if you can tell me what i should do would be great!

[mlatour]

There is no nominal number of turns to set the idle speed screw.

My 2010 YZ125 (same engine as you) service manual simply says to bring the engine up to normal operating temperature (not idling but riding)

and, then set the idle speed to the lowest rpm the engine will idle without stalling.

 

The air screw is typically set between 1.5 and 2.5 turns out,

any more/less is an indicator that your pilot jet is incorrectly sized. 

Edited May 23, 2020 by mlatour