KDXRIDER.NET

Hi Guys, what a great forum!

Here's whats up:

I have a 1998 KDX200 which needs quite a bit of work. It's running but I'm sure it could be better.

I have currently a 48 Pilot and a Main jet 160
Needle on the 3rd position

I'm riding in Wales UK . 116m above sea level.

The problem i'm getting is a crappy top end. at higher revs just poops out. It's fine for working under 15mph but as soon as you want to get a bit faster it's not great.

I set the air mix screw at exactly 4 turns out. I set it like that because the engine revs were highest at that point when idling. Was that the right method? That's how I've set my 4 stroke road bikes before.

Spooging too.

Do those jets seem a good start point you reckon?

Tuning the airscrew out to highest idle is just to determine if the size of your pilot is appropriate. 4 turns would indicate that you need a leaner pilot. After that the airscrew needs to be adjusted for best off-idle response, not fastest idle speed. 160 is probably large on the main, as well. The only way to get it dead on is to follow the jetting guide.

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

You sound rich, Over here in the usa runnin about 145 main, 40 or 42 pilot around 500 ft above sea level.

check engine compression and that the crank seals aren't leaking.
change the spark plug also.
clean the air filter.
make sure the silencer isn't clogged up.

Mix a fresh batch of fuel & oil ( 40.1 ) & a clean & oiled air filter along with a new spark plug.
Pilot jet ...42-45
Main jet ...152-155
Needle in the 3rd position or 2nd
Air screw ...1.5- 2 turns out

If you are not running the air box lid then the main jet may need to be increased to 155-158 if you use a lot of full throttle !

Brill, I wish I could try it out now! I have just ordered a few jets on your guys suggestion. will try them out and see what happens after resetting the air mix.

Fresh plug just in, air filter replaced and re-oiled

Reeds? can these mess up and give those kind of symptoms? it's on my to-check list

The airbox as far as I know is standard and un-modified.


Many thanks,
Jack