I know part of this problem is that I still have stock tires and they dont have much tread left, but at my local track the starting gate and the start of the track are really wet and I usually dont get a very good start and I am a good drag racer so I was wondering what kind of gearing people run for mx, I have stock gearing and I am usually in 4th to 5th gear on most of the track and shift down to 3rd in the corners and then there is one or two corners depended on how they prepare the track that I have to shift down to 2nd.

i like 15/40. It seems to work well for most motocross style tracks

I have run 15/38 w/ 18" rear tires and with 55hp/37tq I would just light up the MRX6's anytime I jabbed the throttle. I've just recently went to 15/36 w/ 18" rear tires and I'm still able to light them up if I'm over generous with the throttle, but it hooks up and just flat out scoots now.