How´s your clutch acting? If it´s not fully engageing, you´re going to find it hard to shift into gear. Try tightening up your clutch cable. If it´s stock, you will find the adjustment in the cable about mid way down the cable as it is attached to your frame. It will easily come off of the fram as the clamps that hold it on slip off and on with a litle elbow grease. Let me know what you find.