Absolutely do NOT do that! You should be running any lower a gear ratio than 14/38. Trust me, you will be shifting even more than you do now, and your wheelies will get worse on the starts. Consider this as well: Think back to when the pros and amateurs were almost exclusively running 250r's. They ran 14/38 up to 15/38 on stock bore motors! You have a 310.
Being slow at off the corners can be a result of two things: either you are normally slow out of the corners due to not carrying enough speed through the corner OR it is bogging you down due to the deep till. Either way, the corrective action is the same: carry more speed INTO the turn to help you get out of it sooner. While the solution is simple, actually doing it is much more difficult to accomplish. lol. It takes a lot of practice. The 4 stroke racers, especially the newbies, are extremely lazy. The go very slow in the corners, because they can use there torque to get back up and going quickly. You can beat the crap out of them by learning to carry speed through the corners. Look at the pros. Those guys carry more speed through corners that most even think possible.
My favorite gearing for mx has been 14/38 and 14/37 on most of my motors (310-363).
From what you're telling me I would suggest the following:
1. Increase the air pressure in your rear tires a little bit.
2. Slightly increase your rebound, little by little. See if it helps.