Blaze,
Unless your bike is in realy bad condition I wouldnt think you would need to worry about the frame. That being said, I wouldnt recomend going out and jumping a line of busses any time soon.
You may want to look into after-market suspension cause off-road bikes like the KDX's usualy have a softer set up because they're not madee to tackle big jumps and would bottom out realy easy, unless you cranked up the stiffness and rebound but if you are only 150 pounds that would probly just launch you off the bike uppon impact (not fun). But aside from that I would look into getting a bit taller gearing and tuning it to put a more high range power instead of low range like the bike comes from the factory.