I have an 04 CRF 50. I have put a uni airfilter, rev box, DPM valve cap breather and fast 50s pipe on it. Has helped top end a lot but bottom end sucks. Whats up? I was out riding yesterday and my buddies 50 that is bone stock can get me off the line everytime. Where did I go wrong. Or what do I need to do to fix it without doing a big bore kit?