Yea mine goes backwards once in a while too. I only get that when using a chicken stick cuz if you dont follow through the whole cycle...I dunno how to explain it...like flip it through the the top dead center. If you dont follow through the pressure might fire the piston back down before it reaches top dead center and will start backward. Well if you cant follow it through cuz its kinda hard sometimes. I never tried this myself cuz I just reach for the electric starter but... if it goes backwards when you flip forward then try fliping backwards, maybe it will go forward