Holes in Air Box Lid

W

wallasaki

Member

May 23, 2002

95

0

• Aug 31, 2002

• #1

Bogs - lost my crisp hit. Smokes worse than ever!!!! Still all stock. Jetting?? Needle clip?? Can't ever seen to get anyone at Sudco on the phone - answering machine.

45 pilot and 155 main sound good?
kdx 2002 200

 

Last edited: Aug 31, 2002

L

Lew

LIFETIME SPONSOR

Aug 27, 2001

605

0

• Aug 31, 2002

• #2

My son's 200 is 155 main and I believe 45 pilot, with clip in #2 position. We ride mainly 3000 to 5000 feet. I would say try adjusting air screw and needle position. I removed his airbox lid completely at the same time we were working on jetting and changed out pipe. So, I do not have a comparison to air box mod with the rest in stock form.
Lew

 

W

wallasaki

Member

May 23, 2002

95

0

• Sep 1, 2002

• Thread starter
• #3

Put the needle clip on the 2nd clip, showed improvement. Tuesday I will order my new jett/pilot from Carb. Parts Warehouse. I cant believe how rich this thing runs!!! Spooge everywhere. :thumb:

 

N

NZMXr

Member

Apr 30, 2002

8

0

• Sep 2, 2002

• #4

I took airbox lid off when bike was about 1 month old and had no problems with it bogging out , the the power increase was good. I did find out that the pilot supplied from new was only #42 and bike did have problems right off the bottom when I was racing but just playing around and on the trails I did not notice it.

 

J

jeffw

Member

Nov 27, 2001

172

0

• Sep 3, 2002

• #5

Mac will probably bust my chops again but imo when you open up the air box the bike runs rich not lean due to increased air flow through the carb sucking proportionately more gas through the jets. That's why leaning the needle helped. Just my opinion, I had the same experience and ended up fitting a restrictor plate till I got some leaner jets since I cut out the top of my box!

 

B

Braahp

~SPONSOR~

Jan 20, 2001

641

0

• Sep 3, 2002

• #6

Try switching to a BR7ES plug or a BR8EG before you change jets.

 

C

canyncarvr

~SPONSOR~

Oct 14, 1999

4,005

0

• Sep 3, 2002

• #7

chop busting 101 ;)

Removal of any restriction on the upstream side of the carb results in a leaner air/fuel ratio.

What gets the fuel out of the carb bowl is pressure differential..not air FLOW. If the differential is greater, more gas enters the air stream. What will make the differential LESS is decreased restriction in the intake area.

(Yes, air FLOW through a venturi results in a pressure differential)

Gas is PUSHED into the airstream by ambient atmospheric pressure. IF the pressures are the same inside/outside the carb...you not be going nowhere.

'Leaning the needle' helped likely cuz things were so rich in the first place. Airbox mods would make things LESS rich, but still TOO rich...likely, probably, good chance etc.

 

J

jeffw

Member

Nov 27, 2001

172

0

• Sep 3, 2002

• #8

CC,

He said it ran fine before the airbox mod, and rich after, just like mine. Even though he said bog, I think he meant blubber since he said it smokes and spooges bad, again, just like mine did.

The increased flow after the mod creates even lower pressure in the venturi, which according to my theory PUSHS:) proportionately more fuel than before the mod. My argument is there is more air AND gas being delivered after the mod and that that mixture is richer.