Hello all, just recently bought an 07 klx250. Seems to run fine till about 7000 rpm then begins cutting out. I went to open up the airbox and the lid is gone. Could it be running too lean? I'm at 6500ft. Thanks

 

Absolutely. If the lid was removed without rejetting that will screw it up, or if it was rejetted for sea level it is now too lean. Did you test ride it at sea level? Was it ok then?

 

No, stupid me I didn't think to rev it out on the test ride so I didn't notice the issue. The test ride was at about 1000 ft lower than me here.

 

Tape up the top of the box until maybe a 1/2" strip is open, then run it. That would be a bit more open than the stock snorkel would have, but you would notice if it runs better. If it works, you need to rejet richer. Two avenues, Kawasaki Kiehin parts or Dyno Jet.

• The Kaw parts (KLX300 needle, richer main and pilot jet) are listed in the Cheap Mods link in my signature.
• Search Dyno Jet for the other.

The Kaw parts also has the more open KDX220 snorkel listed for a bit of protection if you plan some off roading that might splash mud/water up in the bike. I did the cheap mods getting the information from my brother to do them, worked for him. Worked for me too, but we're at about 1000 ft. So the leaner jet would make some sense and the needle might need dropped a notch. I went lean and used a Dial-A-Jet to compensate for elevation change since we can range up a couple thousand feet if down in SE Ohio/West Virginia.