I went out for a little ride. Bike felt a little sluggish.No smoke from exhaust. Pull in the shop check oil. EMPTY. Not my bike, not a chance. I’m vigilant about checking everything all the time! Air box is coated with oil. I pull carb boot and it’s loaded as well. Upon further inspection I find the motor has retained all the oil. I think its a bad oil pump but I never heard of this issue on a 400 ex. Any input?