Stock Main Jet

Joined
Mar 23, 2001
Messages
56
Likes
0
#1
I know there's many posts out there on jetting, and I've read many of them. But now as I'm talking to a parts girl on the phone (literally as I'm typing this), I'm confused because she's telling me the computer says the stock main jet on my 01 KDX 220 is a 142. Is this right? I thought from everything I've been reading that I want to drop DOWN to a 155 main. From what she's telling me, that would be going up to a 155. Am I bass-ackwards here, or is she smoking the good stuff on the job?

I am new to the game. Just turned 140 miles on my new KDX. Pure stock minus the air box lid and Renthal bars.

Thanks:think
 

LoriKTM

Super Power AssClown
Joined
Oct 4, 1999
Messages
2,220
Likes
4
Location
New Mexico
#2
I think her microfiche is wrong. I had this same problem with my KDX. The manual said the stock main was 145 or something ridiculous like that. I went to go order a smaller main jet, and the dealer looked at me like I was nuts! Best way to be sure is to empty the float bowl and remove the main jet, and look at the number printed on the side.
 
Joined
Sep 14, 2000
Messages
502
Likes
0
#3
I think you're getting your bikes mixed up between the KDX 220 and 200. the 200 have the bigger main jets. I believe the stock main on the 220 is a 148 or a 145
 

Mac

Lifetime Sponsor
Joined
May 17, 2000
Messages
505
Likes
0
#4
You have a 220

The 220 carb is smaller and has different jets than the 200 carb. Going down to a 155 main from a 160 main is correct for a 200 or a 220 with a bored carb.
With a stock 220 carb try the following as a starting point:
Copied from http://justkdx.dirtrider.net/
1997 to 2001 KDX220

Stock run a 42 pilot jet,the stock R1173L jet needle in the second from the top clip position, a 142/145 main jet and fine tune the pilot circuit using the air screw.

With a performance pipe/expansion chamber, air box mods , the factory or after-market silencer and the stock 33mm carburetor run a 42 pilot, the stock R1173L jet needle in the second from the top clip position, a 145/148 main jet and fine tune the pilot circuit using the air screw.
 
Last edited:
Joined
Mar 23, 2001
Messages
56
Likes
0
#5
Does that mean that the 160 main is what comes stock then? And is a 42 pilot jet stock also, or is that something I need to purchase as well? If 42 is stock, then that would mean I would only need to pick up a 145 and/or 142 main for a couple bucks. I'm having a friend, who is a bike mechanic on the side, give me the lowdown this weekend. So hopefully after that it will all become more clear once I can see what things look like in there. I've always just had cabin cruiser 4 strokes (XR200) where you kick and go and change oil once or twice a summer.

-Thanks
 

Canadian Dave

Super Power AssClown
Joined
Apr 28, 1999
Messages
1,202
Likes
0
#6
No your KDX220 comes stock with a 145 main jet and the KDX200 comes stock with a 160 main jet. They use different sized carbs and therefore different jetting. The KDX220 has a 33mm carb and the KDX200 a 35mm carb.

Your 220 has a 42 pilot jet stock. You'll likely only need to pick up a 142 and a 148 main jet (the 148 incase you decide to install an after market pipe down the road). I'd try a 142 main, move the jet needle's clip to the second from the top position (#2) and fine tune the pilot circuit with the air screw. Make sure you do a plug reading at WOT to insure you aren't running lean and take it from there.

David
 
Joined
Mar 31, 2000
Messages
68
Likes
0
#7
Dave, I also run 42, 142, stock needle 2nd clip per your recomendations. A year ago when I did this I bought a 142 main jet and removed the stock jet, only to find a 142 already installed.....Is it possible the dealership dropped a jet size.
 

Canadian Dave

Super Power AssClown
Joined
Apr 28, 1999
Messages
1,202
Likes
0
#8
It could be that the dealer installed it or it could be that some KDX220 are being delivered with 142 mains from the factory. I know when I picked up my 98 from the dealer the pilot jet wasn't what the manual or dealer info specified it would be. My dealer definately didn't change it.

David
 
Joined
Mar 23, 2001
Messages
56
Likes
0
#9
Heading to dealer today to buy 142 & 148 mains. Will start out with 142, 2nd down, and tune the screw.

Thanks Dave for clearing things up.
 
Joined
Mar 23, 2001
Messages
56
Likes
0
#10
a little long but interesting

Ok, so I go to the dealer last night after work. I tell them I want a 142 main and the guy says "Why?, what's it doing?" I say, "well, umm, duh, I dunno, first gear kinda sucks, seems boggy, but 2nd and 3rd fly, and everybody on the net says that I need one." He says "You don't need a new main. Leave it like it is, and just move the needle clip. Here in MN at 700ft, with varying temps (one day it's 60, the next is 90, which is true), it's better to run phat (rich)." Then he gives me the "I used to race Team Green, never had to change main, etc". He then asked what kind of oil I use. I told him Bel Ray SL2-SemiSynthetic. He says "oh, that's not what you wanna use, you wanna use Yamalube-R. Mainly because it has rust inhibitors and Bel Ray doesn't." :think The guy seems to know more than I do, which isn't saying a whole lot, so I took his word for it and left without buying anything.

Here's the kicker, the main reason I didn't buy one anyway. They wanted $9.55 apiece!!!:eek: Sounded outrageous. Sooooo, I'm riding tomorrow big time and just gonna try moving the needle deal and see what happens.

Thoughts anybody?????????
 

DANIEL JOSEPH

Damn Yankees
Joined
Sep 14, 2000
Messages
502
Likes
0
#11
He could get you one (If you decide you need it) from Parts Unlimited for probably $3.75 its from Mikuni part instead of Kawasaki. I think the Parts Unlimited P/N is D18-3142
 
Last edited:

DANIEL JOSEPH

Damn Yankees
Joined
Sep 14, 2000
Messages
502
Likes
0
#12
Last post I wrote Mikuni Jets. Why didn't someone slap me.
Now the correct info. You can buy any Keihin jet from your dealer though Parts Unlimited. Only problem is that Parts unlimited now sells them in packages of 5. P/N D34-4142. Any Dealer should be able to break down the pack and sell them under P/N D31-3142 for 3.99. Do not pay 9.99 for a main jet from Kawasaki when you should be able to get the same jet for 3.99
 
Joined
Mar 23, 2001
Messages
56
Likes
0
#13
I may have to try that angle. $10 is a bit ridiculous.

Put on 113 miles on the KDX220 this past weekend. And we only did 30 the first day. Went thru some great terrain. Mostly ATV/snowmobile trails. But everything is so wet up here in MN that it was a blast crashing thru puddles, 20 foot mud roosters, etc. Went with 4 guys all in one truck and one trailor. We had a variety pack of a 99 RM250, 98 CR250, 00 YZ426F, and my Green machine. I was known as the "water moccasin" because the KDX was the puddle tester. Liking the bike more with each ride. It did start shifting harder towards the end of the trip, and it stuck in neutral on me between 1st and 2nd a couple times. Gonna try changing fluid and see if it helps. Have 200 miles on current tranny oil.

Almost time to start the mods.

seeya