Bigger slow jet, or smaller?

Got questions? We got answers....
Post Reply
superman27e
Member
Posts: 220
Joined: 03:39 pm Jun 30 2014
Country:

Bigger slow jet, or smaller?

Post by superman27e »

My 1999 KDX 220 will not idle right. I've cleaned the carb, jets, and passages so many times, it's crazy. I've checked for air leaks, ect. One thing it's doing is it'll fluctuate rpms at idle. It'll idle how it's supposed to, then increase, then decrease. Also, if I lean it to the left just a little, the rpms will get higher. But once I hold the bike upright, the idle rpms get real low. That made me think float height. I checked it, and it was fine and working like it should.


The only mods are a fmf silencer and boyesen reeds. The jets are stock. 160 main and 48 slow. I believe that's stock, right?

Is it a slow jet problem? Because when I'm riding it, it's pretty boggy in first and second, but past that and at the power band, it runs great.
JasonK94Z
Member
Posts: 133
Joined: 06:38 pm Oct 12 2013
Country:
Location: Moore, OK

Bigger slow jet, or smaller?

Post by JasonK94Z »

http://www.kdxrider.net/forums/viewtopi ... 105&t=1156

How many turns out from seated us your air screw?
2002 KDX 220R
2003 KLR 650
superman27e
Member
Posts: 220
Joined: 03:39 pm Jun 30 2014
Country:

Re: Bigger slow jet, or smaller?

Post by superman27e »

I can take it all the way out and it does absolutely nothing. If I go all the way in, it dies.
User avatar
Postigo
Gold Member
Gold Member
Posts: 372
Joined: 10:09 pm Aug 12 2012
Country:
Location: Puerto Rico
Contact:

Re: Bigger slow jet, or smaller?

Post by Postigo »

Got the same problems two years ago with my 220, check your crank seals first no matter what you do with the bike if the engine is getting air from the stator side seal she will idle only when the engine is cold, just remove the the stator cover and check for oil or gas leaks to make sure you dont have problems with that seal. Another problem coul be the float height or bad jet block gasket. Hope this helps
The Doctor says I have multiple personality desorder... But we are not agree...
User avatar
Tedh98
Supporting Member II
Supporting Member II
Posts: 1576
Joined: 01:08 pm Mar 20 2009
Country:
Location: Atlanta, Georgia
Contact:

Bigger slow jet, or smaller?

Post by Tedh98 »

superman27e wrote:The jets are stock. 160 main and 48 slow. I believe that's stock, right?
On the flywheel side of your cylinder, right where the reed block bolts in, there should be a 4 digit number. Yours isnt 1742 is it?
superman27e
Member
Posts: 220
Joined: 03:39 pm Jun 30 2014
Country:

Re: Bigger slow jet, or smaller?

Post by superman27e »

Yea, it says 1742.
User avatar
Tedh98
Supporting Member II
Supporting Member II
Posts: 1576
Joined: 01:08 pm Mar 20 2009
Country:
Location: Atlanta, Georgia
Contact:

Re: Bigger slow jet, or smaller?

Post by Tedh98 »

You have a 200. Looks like the red KDX is at it again.

I was wondering why your "220" had stock 200 jetting.

Your jetting is likely too rich. I run a 40 and a 155. But as stated, you really have to go through the jetting process to find out for certain.
superman27e
Member
Posts: 220
Joined: 03:39 pm Jun 30 2014
Country:

Re: Bigger slow jet, or smaller?

Post by superman27e »

Wow. That dang red KDX. I always figured something was up. It has a purple seat, and I don't think the 220s had purple seats in 1999. If that's even the actual year model it is...was....I don't know, haha.
superman27e
Member
Posts: 220
Joined: 03:39 pm Jun 30 2014
Country:

Re: Bigger slow jet, or smaller?

Post by superman27e »

So where can I get different jets?
User avatar
Tedh98
Supporting Member II
Supporting Member II
Posts: 1576
Joined: 01:08 pm Mar 20 2009
Country:
Location: Atlanta, Georgia
Contact:

Re: Bigger slow jet, or smaller?

Post by Tedh98 »

I use jetsrus.com
superman27e
Member
Posts: 220
Joined: 03:39 pm Jun 30 2014
Country:

Re: Bigger slow jet, or smaller?

Post by superman27e »

Thanks! I'll give it a try and go from there. Stay tuned, more crazy surprises from the infamous red KDX to come :p
jovan
Member
Posts: 15
Joined: 06:06 am Jul 26 2014
Country:
Location: Serbia(EUROPE)

Re: Bigger slow jet, or smaller?

Post by jovan »

I had one similar problem, my jets are 42, 145, and its fine for now, maybe you have rich jets, but the problem was in the cable witch is on the top of carburetor, when l move a little wheel left or right, he play with rpm-s, because wheel pull the cable for gas, up and down, and on the top of the carb you have one clip, on mine bike was worn, and l fixed it with one small extra wire inside and for now is fine...
User avatar
diymirage
Supporting Member II
Supporting Member II
Posts: 2909
Joined: 05:00 pm Sep 19 2011
Country:
Location: michigan

Re: Bigger slow jet, or smaller?

Post by diymirage »

superman27e wrote:Wow. That dang red KDX. I always figured something was up. It has a purple seat, and I don't think the 220s had purple seats in 1999. If that's even the actual year model it is...was....I don't know, haha.

look at your VIN, if the 10th digit is a X it is a 99
newbbewb wrote:DIYmirage has it right.


-1996 KDX 200 woods weapon (converted to 99 green body)
-1996 KDX 200 plated street toy (barney edition)
-2003 Yamaha TTR125-L (wifeys bike)
-1997 KDX 220 project bike
Post Reply