Just another jetting confirmation

Got questions? We got answers....
Post Reply
santod
Member
Posts: 20
Joined: 07:59 pm Oct 03 2005
Country:
Location: Atlanta, Ga

Just another jetting confirmation

Post by santod »

1997 kdx 200

fmf rev pipe
rad valve
no lid
new top end
no leaks
ga, High Humidity and temp usually 700 ft alt

I was able to get the stock needle (clip 3) to work ok with a 42 pilot and 155 main but there was a lean spot at about 1/4 throttle. There was really no power until about 1/2 throttle and then boom. It was fun for awhile but by the end of the day it would tired me out.

After reading many post on this board I moved to a CEM needle (clip 2 from top) (sudco had the CEL on backorder). Today was my first ride on it with a 40 pilot and 152 main. I am very happy with the power delivery and smoothness. The bike now has awesome low end response. I can loft the front wheel now without being on the pipe and 1st - 4th.

The only issue I can see is that it still seems a bit lean at about 1/4 throttle but if I go anymore richer (about 1.5 out) on the air screw I foul plugs on idle.

Does anyone have any suggestions smaller pilot different needle?
AZRickD
Member
Posts: 524
Joined: 08:51 am Jun 29 2006
Country:

Post by AZRickD »

Don't do what I did, but...

I went with a 35 pilot.

Phoenix. 105 F, 1200 feet, 12 % humidity.

Rick
I done KX-ed QuailChaser's KDX220R
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

re: ' but if I go anymore richer (about 1.5 out) on the air screw I foul plugs on idle.'

FTR, please expand a bit on that statement.

Move your clip to -3 if for no other reason than to know it doesn't work.

You have tried the 'D' series and didn't like them?

Considering Sudco's shipping and handling fees it doesn't pay to order one part at a time......

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
santod
Member
Posts: 20
Joined: 07:59 pm Oct 03 2005
Country:
Location: Atlanta, Ga

Post by santod »

I did try clip position 3 with the CEM needle. It was really rich at 1/2 throttle and the power delivery was poor.

As for the idle and fouling plugs I was a bit shocked. I started with the air screw at about 1 1/2 out and fouled a plug from a cold start. Changed the plug and moved the air screw out and fouled another one. So another plug went in and the air screw out more and I was in business.

As the day and bike warmed up I was able to adjust the air screw back closer to 1 1/2 turns.

I have not tried the D needles yet I ordered a bunch of C and B needles so I guess D is next.
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

Just get it RB'd. Then there is no guessing and there are 2 needles that are optimum for it. CEK and DEK. Wild or Mild respectfully.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
KDXer
Supporting Member
Posts: 2845
Joined: 12:11 pm Nov 12 2004
Country:
Location: Sydney, Downunder

Post by KDXer »

>|<>QBB<
Indawoods wrote:Just get it RB'd. Then there is no guessing and there are 2 needles that are optimum for it. CEK and DEK. Wild or Mild respectfully.
What he said... :supz:


RESPECTIVELY even. :wink:
Image

"I want to die peacefully in my sleep like my grandfather, not screaming in terror like the passengers in his car."
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

IMO and all...but if plug foul is determined by bits of AS position, something else is quite a ways off.

I assume that was with the 42, not the 40?

My own experience with the 'B' needles followed what JD (the jetting guy) has said. Basically (rough paraphrase), the 'B' can't ever be tuned to work..it's whacked to start with.

The above mentioned 'K' diameter is for a #7 slide.

I haven't tried them with a #5 (OEM), but the 'M' choice is correct for that slide I believe. Certainly close.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
NM_KDX200
Member
Posts: 314
Joined: 09:24 pm Aug 18 2005
Country:

Post by NM_KDX200 »

Well, you guys got me all encouraged to go work on the jetting of my KDX. It's been running on "winter" jetting of 150/40/1173-2 and honestly has been running pretty bad. Lots of smoke on start up, long warm-up, and a generally "sluggish" feel when riding. Temps in the 80-90's, humidity is around 40-60%, pretty high for us, but we've had rain. (this is New Mexico, after all).

I took the carb apart, cleaned everything up, popped a 148/38 combo in, set the AS 1.5 turns out and tried it out. I immediately noticed a faster warm-up. Right after starting, it sounded crisper and it warmed up much faster (that is, it took throttle sooner). I did a bunch of 1/8 throttle roll-ons and like what I was feeling. Messed with the AS and ended up right at 1.25 turns- definite difference between 1 and 2 turns. 1.5 was good, but 1.25 was just a little bit crisper. Then I changed the needle from 2 from the top to middle and I liked that better. Mid-range had more power and pulled stronger to full throttle. I can roll it on from 1/8 and it'll lift the front wheel and carry it all the way thru. Runs MUCH nicer than it did before I started. I had a lot of fun roosting thru my little play track- I'll tell ya what, that KDX digs deeper ruts than the KX125.

So, I ended up with:

New Mexico
6000' (thousand, not hundred)
85 deg F
50% RH
KD200
airbox 1/2 open
FMF Desert
FMF ISDE Turbine Core
Boyesen Pro reeds
1173/3
148 main
38 pilot
AS = 1.25
32:1 Yamalube 2R
1999 KDX 200
2001 KDX 220
2002 RM 134
2004 KX 125
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

See y'all?...what happens when you take the time to get this jetting junk sorted out?

Yeah, it may take some time to start but once you DO get it sorted out you know what to do when, know what to expect, and how to change 'it' (whatever the throttle part of 'it' is).

The result is more fun!!

That 'crisp' part is important. Part of the 'seat of the pants' input of jetting. You can hear the exhaust note change (example) from the tip of the S/A to further down INside the pipe..and you FIX it. Why?

Because the result is MORE FUN!!.

Coolio!!

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
NM_KDX200
Member
Posts: 314
Joined: 09:24 pm Aug 18 2005
Country:

Post by NM_KDX200 »

>|<>QBB<
canyncarvr wrote: You can hear the exhaust note change (example) from the tip of the S/A to further down INside the pipe..
It's true. That's what I used to guide me while working on the A/S. The exhaust tone changed. It was a clear difference between "whooorrrrrr" and "wiiiiiiinnnnnnggggg". 1/4 turn made it go "wiiiiiiiinnnnngggg" and that's where I left it.

Next time I think about it, I'll order some needles. I'm still on the stock needle.
1999 KDX 200
2001 KDX 220
2002 RM 134
2004 KX 125
User avatar
Actarus
Member
Posts: 57
Joined: 12:32 pm Apr 24 2006
Country:
Location: Vald'Or, Qc

Post by Actarus »

Is there anything to be done about Mikuni carbs or is it useless ?

A VM34SS to be more precise.
1981 KDX 175
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Mr. Black does work on Miks, too. Did on our Banshees, to excellent effect.

You might ask him if your genuinely interested in getting it worked on. If you're just mildly curious I wouldn't use his (or anyone else's that does that sort of work for a living) time.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
Actarus
Member
Posts: 57
Joined: 12:32 pm Apr 24 2006
Country:
Location: Vald'Or, Qc

Post by Actarus »

I was simply curious about it.

Thanks !
1981 KDX 175
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Not being snotty about it....imagine running your own one-man shop..and the phone rings 30 times a day from people 'curious' about stuff.

I'm in a service business. I deal with that all the time. The shop rate is $72/hr (has been since '96), but some people have NO problem TALKING to me for over 30 minutes about NOTHING germain to their problem. Now, I could tell them, 'Please shut up and get the hell out of my shop!' Now THAT would be snotty, 'eh?

And, no...the particular instance I'm thinking of, nothing short of that comment would have gotten the customer out the door! That happened on the contact call, when the equipment was delivered and when it was picked up! I spent a good three hours on him and his machine, charged him for an hour...and he BITCHED about THAT!! It was dead-nuts broke when he brought it in, it worked perfectly when he picked it up. AND he was SO worried about losing his data..which he certainly would have had I not FIXED his machine (his fault it was hosed in the first place).

No, I'm not saying you are like that...or anyone else in particular. If I knew anything about the Mik on your bike I'd be more'n happy to spout off about it. But I don't.

Sorry.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
Post Reply