Pilot Air Screw
Posted April 09, 2003 - 04:42 AM
On an interesting note, I also put a new Hi Flow header on. After running it for a while, the header changed color from it's nice new aluminum shade to a almost reddish hue. Could this be a clue as to were to direct my attention???
Posted April 09, 2003 - 05:53 AM
After all the jetting work I've done, this is the best I've been so far. The only problem I have is that there is a "blip" at the bottom when snapping the throttle. I'm still working on this.
Posted April 09, 2003 - 05:56 AM
Posted April 09, 2003 - 06:20 AM
Posted April 09, 2003 - 06:53 AM
Posted April 09, 2003 - 08:35 AM
Smurf blue F150 and a WR with a brand spanking new black YZ fender
I'll probably be leaning over my bike working on the jets.
Posted April 09, 2003 - 09:26 AM
e-z_e, am I right? Did you get a pilot air screw from Sudco or some other place? Your bike doesn't come stock with one. The pilot air screw (PAS) replaces the pilot air jet (PAJ) which is located at the intake on the face of the carb. If you did, it depends on your pilot jet. I'm running a 35 pj, so I have my PAS set to 1/4 turn out, equivalent to a 45 PAJ. If I recall correctly, a 38 PJ needs a 65 PAS (3/8 turn out), a 40 - 1/2 turn out, 45 1 turn out. Seems to be 1/8 to 1/4 turn out for each larger increment.
Now, if you aren't talking about a PAS, then you must be talking about the fuel screw. These carbs don't have an air screw that is externally adjustable. I emphasize this because air screws (like 2-stroke carbs have) and fuel screws work oppositely from each other. You turn an air screw out to lean the mixture while turning out a fuel screws richens it.
You optomize the fuel screw setting at high idle. Warm the bike up and adjust the idle up pretty high with the idle adjust knob. Now turn the fuel screw to where you get the highest idle. If you need to go more than 3 turns out, it needs a bigger PJ. If you need to go less than 3/4 turns out, you need a smaller PJ. Once you get the fuel screw set properly, then turn the idle back to where you want it with the idle adjust knob.
Posted April 09, 2003 - 02:07 PM
Until then, thanks!
Posted April 09, 2003 - 06:02 PM
Posted April 10, 2003 - 08:28 AM
Posted April 10, 2003 - 08:42 AM
Posted April 10, 2003 - 09:00 AM
Posted April 10, 2003 - 09:22 AM
Do the air jet changes make a large difference in how the bike runs, or, is it a safety thing for getting the correct ratio's of fuel to air?
I am fixin' ta order a PAS, a 200MAJ, kouba T-Handle, and EKP needle from sudco (and extra circlips) Any opinions?
Posted April 10, 2003 - 10:08 AM
Posted April 10, 2003 - 10:52 AM
Thanks for the help
Posted April 10, 2003 - 11:13 AM
I'll save ya some time...maybe...
At altitude (5K), I tried and tried and tried to make an __M or __N needle work...to no avail. Too rich. The richest needle I could get to work was the EKP...and thus my jetting setups listed below. Perhaps you can by not using a setup anywhere close to the "recommended" PJ/PAJ ratios (as Rich explained above), but I wasnt able to find any that would work.
Let me know if you do some testing with them and do get them to work...
Posted April 10, 2003 - 11:14 AM
Go to Fay Myers, they have a bunch of Zip Ty fuel screws, I just got one there the other day.
To add to what Rich said, the proper PAS adjustment combined with PJ seems to make the whole pilot circuit run a lot crisper. The combination in my jetting (very similar to LarryCO's with the exception of the 148 mj) runs great, pulls hard in all ranges and there is absolutly no bog. I think I can leave my jetting alone for a while until I go up to 13,000 ft, then I'll switch back to the EKQ #2.
Posted April 10, 2003 - 12:24 PM
Posted April 10, 2003 - 12:59 PM
You can't move dude!!! We have guards at the border. Thanks for the help!! I hope that the YZ timing may make a difference in my bike.....We will see!