pilot air screw, and spring?? Whaaa?

3 replies to this topic
  • ballistic

Posted July 04, 2001 - 06:02 PM


I was reading the threads on jetting, and plan on trying out the EKP needle in my DRZ, as per JD's suggestion (got it finally!).

But what is the pilot air screw and spring which I have read about in some posts?
What is it replacing?
What is part #?

Any advice appreciated. I've tryed reading threads on it but it still seems cryptic, even esoteric... :)

  • James_Dean

Posted July 05, 2001 - 07:28 AM


The pilot air screw is a replacement for the pilot air jet (#75 or #100 is stock). This adds another degree of adjustability to the pilot screw (fuel screw). The pilot air screw needs the spring to hold it's position.

The carb is designed with this special feature to allow either the pilot air jet OR a pilot air screw. The problem is that it is very difficult to get to and adjust because it is located in the mouth of the carb and hidden by the air-boot AND the adapter flange.

If you don't want to spend a lot of time experimenting, get the #100 pilot air jet and your settings will be comparable to most others running the EKP. Otherwise Sudco has the spring and screw - Part # 021-235 and 021-230. (1-800-998-3529)

There is a picture of it in the exploded parts view of the FCR carb (street bike carb) at www.carbparts.com (option 30A and 30B)

[This message has been edited by James Dean (edited 07-05-2001).]

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  • ballistic

Posted July 05, 2001 - 11:03 AM


Thanks for the info there, JD. With that info, I'll skip the adjustable and stick with the #100.

I am taking the liberty to experiment with jetting for the benefit of us DRZ riders, cause so far very little has been done.

What start baseline settings should I begin at with the EKP?

--Air jet #200?, or remove #200 for #230 equivelent?
--clip position #3?
--screw out 1.5 turns?
--main jet #158?

I have and plan to try #156, 158, 160, 163 and 165. Do I change clip position and # of screw turns for each different MJ?
Thanks again for your help. Im hoping this will lead to some good performance gains.

  • James_Dean

Posted July 05, 2001 - 01:27 PM


This is from another DRZ owner:

100 pilot air
48 pilot jet
1.5 turns on pilot srew (fuel screw)
EKP clip #3
200 main air jet
158 main (Yoshimura Exhaust)

You will want to experiment with the mains, try going 2 steps at a time. Keep the clip the same unless it shows signs of rich or lean. Adjust the pilot screw in the range of 3/4 to 1 3/4.

The main jet increments are 155, 158, 160, 162, 165, 168, 170...

Good Luck, expect the mid-range to come alive! :)



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