Fouled Plug Blues

M

Moose95

Sponsoring Member

Mar 9, 2002

328

0

• Apr 7, 2002

• #1

I've got a new KDX 200, ('01 left-over). I've just finished the break-in process for the engine. However, I'm fouling plugs left and right. I believe that I'm running the engine hot enough to burn the oil, but riding on tight terrain/thick woods...I may not be. I'm running the pre-mix 32:1 using Yama-Lube and a NGK BR8ES spark plug. My air filter is clean and lightly oiled, is there anything I'm missing here?

 

R

ride_red_15

Uhhh...

Oct 14, 2001

574

0

• Apr 7, 2002

• #2

your air screw is probably in too far, and your jetted way too rich

 

K

KiDX

Sponsoring Member

Mar 30, 2001

404

0

• Apr 7, 2002

• #3

The stock jetting is too rich, it's gonna have to be leaned out. Check out the JustKDX website for some jetting help.

 

B

BRush

LIFETIME SPONSOR

Jun 5, 2000

1,100

0

• Apr 7, 2002

• #4

For the short term, use a BR7ES plug. This is a much better heat range for anyone who is riding woods/tight terrain. It will stay hotter and resist fouling better, It will not hurt your bike. This is my main plug.

Ultimately the underlying cause is jetting. Factory KDX jetting is notoriously rich. For some good starting points to rejet your bike, see the JustKdx web site:

http://justkdx.dirtrider.net/carbtuning.html

Once the jetting is right, a KDX almost never fouls a plug.

 

M

MassKDX

Member

Dec 11, 2001

128

0

• Apr 8, 2002

• #5

I would suggest for starters go with a 155 Main and a 45/42 Pilot. I made this adjustment to my bike and it seems to be almost dead on. I could lean it out one more but I am happy with my KDX's performance.

 

C

canyncarvr

~SPONSOR~

Oct 14, 1999

4,005

0

• Apr 8, 2002

• #6

'Just finished the break in..'? What did you do for the NEXT 10 minutes? ;)

When you get around to changing to a more reasonable ratio of premix (say 40:1), keep in mind that you are making it RICHER when you do that...so whatever problems you have now are going to get worse.

Note the hop-up section on justkdx. Under 'Is there anything I'm missing.' check out the airbox mod.