Start with the basics. Clean and lube the clutch cable, then check the pushrod adjustment.
the tip of the clutch arm is pointed and when pushed forward with your finger should align with the raised edge on the engine case below it. If it does not the push rod will need to be adjusted.
FWIW use the clutch to shift. just because it can be done( clutchless shifting ) does not mean its good for the transmission. it wears off the edges of the engagement dogs and tweeks the shift forks. I have also had to replace many busted shift drums on customers blasters to. Use the clutch.