I dont see the timing changing on the motor just from running over time, it would either be in time or out of time. Followed everything to a t installing it. Ran great for a while. yeah going to trouble shoot from tank to carb, pretty sure it is somewhere in there. I'm really leaning towards a clogged jet at this point, Just for the fact I found no water in the float or tank. And t he gas was pretty cloudy not the clean clear look it should have. Guess we will see!