Professional jetting for my 2003 KX250 in Orlando?

svttodd,

Send me an email and I'll help you get it dialed in for your conditions. It shouldn't be difficult with the right parts.

James
JDJetting@comcast.net

If your trailriding your MXer first thing you should do is change the spark plug your using. Instead of the Iridium plug that the bike calls for stock go to a bigger electrode plug like the BR8EG. Bigger electrode, less prone to fouling. I would change your premix ratio as well. It should be 40 to 1. Make sure as well that your not over oiling your air filter. When it comes to jetting on my bike I like to jet it just a hair rich. Not till the point that its dripping spooge out of the silencer or doesn't run cleanly, just rich enough so tempature changes doesn't affect the bike as much. The only problem I had with the stock jetting was that the main jet was to fat. It jetted very cleanly up till I got it on the main. Then it would splatter paint (spittle) the rear fender black. One size smaller was the trick for my application. To get the bike to idle just turn the idle up a hair. It's no (stock) KDX so don't expect it to sit there contently idling away without loading up. Also don't let the bike run on the choke when you intially fire it up. Start it up and turn the choke off right away.

I wouldn't mess with the heat range, just a larger electrode plug IMO is much less prone to fouling off-road. I know the reason the manufactures equip their bikes with these exspensive Iridium plugs with the tiny electrode, but I discovered that the small electrode is more prone to fouling out as well as watering out. Also since riding off-road puts different demands on the bike then MX does there is no need for the Iridium plug. I've ridden and raced in Florida before (big scrub and the Alligator Enduro) and do not need to change my settings from what I run up here. My set-up is different then yours, I'm sure (V-Force, stock head pipe w/ FMF Q-Silencer, stock motor w/ lighting coil {flywheel effect}). Your jetting is most likely not far off from were it needs to be; just change the pre-mix ratio, try a UNI air filter element as opposed to the thicker stock unit and a BR8EG. You then should find that the jetting it has now should work a little better. Also if it spooges that much, try repacking the silencer; it's probaly full of black crud.

Man, I live inOrlando and I owned a 03 KX250, now an 04 and hopefully soon an 05!

Jetting a bike is not rocket science and you don't need a pro rider to do this. In fact, a lot of pros aren't very good mechanics.

Mine was running very crisp. The bike comes very close from the factory. 40:1 is a good start to get rid of the spooge(but it's OK to have a little if the bike idle long) Air screw should be enough to fix your issue and worst case, a leaner pilot.

I'm at Bithlo and Pax all the time, stop by and say Hi, I'll help you out. #47 on a Seminole Powersport KX250 / No fear gear.