2001 KDX 220 carb questions

[MDKDX]

Ok members I have read so many carb threads & learned one thing for certain RB is retired and no longer doing carbs, now my 220 is going through a full rebuild too to bottom K am doing a Fredette port, head mod, AND the pipe, I was going to send my carb but I think the jet block is worn out so I want to purchase a new Genuine Keihin carb & I am thinking on just going with 35mm to save some bottom end power.


Now I see something on #7 slide mod , so my question to members that have dealt with this what are your thoughts on which direction I should go ? I am a heavy rider and do not want a KX style power band I want to be able to ride slow and when trail opens run it out not the low rev 220 band
Thanks in advance

[John_S]

My experience with a 220, 35 air striker carb from jets r us, rb head, and rev pipe is don’t get the #7 slide. I think it would work better on an old carb. Worn out carbs and slides run real rich on the pilot.The air striker comes with a 4.5 slide and it was perfectly fine. With that set up I had:
40 pilot
Jd red needle 2nd clip
145 main
Air screw 1.5 turns out

Always searching for more, I bought a #7 slide and it was still lean with the air screw at 1/8 turn out. Dialing it in I ended up with:
50 pilot
Jd red 3rd clip
145 main
Air screw 1 1/8 to 1 1/4 turns out. The air screw is super sensitive.

There is no advantage to starting, idling, or throttle response. It runs great but just the same as before with larger jets. I even went up size by size on the pilot 42, 45, and 48. All of them had the air screw at less than 1 turn and even a little off could induce a lean bog real quick or when you let off the gas you’d have that “dun dun dun” run on sound instead of a clean drop in rpm’s.

A brand new genuine Keihin 35 (air striker or standard) should be all you need.

[MDKDX]

My experience with a 220, 35 air striker carb from jets r us, rb head, and rev pipe is don’t get the #7 slide. I think it would work better on an old carb. Worn out carbs and slides run real rich on the pilot.The air striker comes with a 4.5 slide and it was perfectly fine. With that set up I had:
40 pilot
Jd red needle 2nd clip
145 main
Air screw 1.5 turns out

Always searching for more, I bought a #7 slide and it was still lean with the air screw at 1/8 turn out. Dialing it in I ended up with:
50 pilot
Jd red 3rd clip
145 main
Air screw 1 1/8 to 1 1/4 turns out. The air screw is super sensitive.

There is no advantage to starting, idling, or throttle response. It runs great but just the same as before with larger jets. I even went up size by size on the pilot 42, 45, and 48. All of them had the air screw at less than 1 turn and even a little off could induce a lean bog real quick or when you let off the gas you’d have that “dun dun dun” run on sound instead of a clean drop in rpm’s.

A brand new genuine Keihin 35 (air striker or standard) should be all you need.

John
First off thanks for reply I appreciate it, question what is "JD" needle ?

[John_S]

JD Jetting is a company that makes needles. There was a 100 page post WAY back where James Dean of JD was chatting with the guys on this site and starting to develop the needles. He said both of them are close to and based on the Keihin needles, CEL for Red and DEL for blue. I’ve tried all 4 back to back in the same day and without a doubt my particular engine runs best with the red needle. The CEL would’ve been fine also but had more of an MX style hit where the red one transitioned onto the pipe smoother. Lugging the engine in the mid range a gear higher is where the red one shined for me. With carbs costing as much as they do now, you can save some money if you want and get a new carb and the cel and del needles. The del is mellow in comparison.