Hi

Can anyone advise what is the correct setting for the air screw on the carburettor on a 2013 Evo 250?

What is the procedure for fine-tuning the adjustment?

 

Thanks          

2 & 1/2 turns out is stated in the owners manual.

 

Fine turning is by feel/ear.

Best using 1/4 turns from your base setting (2 & 1/2)

 

Richen up too far and the engine will sound dull and laboured.

Lean out too much and it'll not settle back to an even idle after blipping the throttle, it'll ring a ding ding!

 

You're after an even, smooth idle that responds to the throttle cleanly, yet returns back smoothly to an even idle after blipping.

 

Also worth noting that mixture screws on different carbs work different ways.

If the screw is behind the slide (airbox side) it effects the air,

winding out leans and winding in richens.

Like the Keihin.

 

If the screw is after the slide (engine side) it effects the fuel,

winding out richens and winding in leans.

Like a Delorto.

Edited May 29, 201511 yr by goudrons

Keihins are rather touchy about moisture in the pilot circuit. I find that when my bike starts acting a little odd at low throttle settings it's due for a disassembly and clean with compressed air. This includes pulling the center tower that can be removed with a Torx security bit. I have to do this about twice a year.

Is it a 2T?  If so, baseline is 1.5 turns out from fully in. I'm usually running about 1 turn out.