KDXRIDER.NET

I modified the air box cover but left the front 1/4 intact so the CDI unit
would still have a mounting spot.

Do I need to consider rejetting at 700 ft or are the bikes plenty rich with
the factory stock jets?

This bike also has an FMF pipe and silencer

are the bikes plenty rich with
the factory stock jets?

Generally, yes. While that may help it doesn't mean your jetted right. Doesn't mean your bikes going to foul plugs either. KDXs are fairly tolerant. To get the most throttle response, and fuel mileage most go in search of much tigherter jetting. Do a search on here and you'll find lots of stuff.

Also a good tutorial HERE