I have a JD790 and when I started it the other day it made a pop that sounded like an air hose burst and when it started it sounded like an exhaust vale was stuck open. Anyone had anything like this happen to them??
Hmmmmm, most Diesels have very little if any clearance for a valve that sticks open and you would defenetly hear a piston wacking a valve that stuck open. (In reality, the piston would unstick the valve very quickly but would most likely bend the stem.)
What may be more likely is that you spit out either the glow plug if equiped or the injector. Pop the hood and take a look for those first before you yank the cover, may save you a lot of work.