When cleaning the carbs I bumped the plastic cap that covers the air adjusting screw on the top carburetor and broke the screw off. I already have extracted the screw without damaging the theads and have ordered a new screw. My question is what is the default or factory setting for the screw. I know I have to seat the screw then back it out x amount of turns. I realize I could guess and then adjust for smooth idle but I would like to start it as close to the one on the botton Carb as possible. Any help or ideas would be appreciated.
I'll start at two I guess. If I wasn't afraid of breaking the one on the lower carb I'd pop of the plastic cap and see how many turns out it is. They put these caps on there from the factory so they can't be adusted. I think for emissions reasons they set them as lean as possible and then set them semi permanent with the plastic caps so they can't be messed with. Anyway it will probably be fine at two turns, I was just wondering what the factory sets them at.
the factory sets them with a flow bench, us poor techs simply get to go by the spec in the manual which is what I gave you.
yes the caps are EPA mandated and yes if you pop it off there is a good chance you will get to extract another broken needle.
dont worry, even us experienced techs get to break them off.
Duroc did the two turns work for you? I did the same thing by breaking the air screw. Going to go pick one up today. But took the cap off the bottom carb and found that it was two turns as well. Can the two carbs have different settings? Or what you do to one you need to do to the other? I guess what I am asking is how do you know which carb needs to be adjusted if its running rich/lean?
Yamaha 25hp ELR Air Adjusting Screw
Linear Mode
