Good afternoon all. I'm having trouble with my 250. It was running well a week ago, now it won't start. It cranks, but won't fire. It has spark and plenty of gas. A few things that I noticed was that air is puffing out of the carburetor. I suspect the cam has jumped a tooth or two, but is that even possible with these engines? The ignition rotor does not point at the #1 terminal when the motor is at TDC. It is closer to the #4 terminal. Compression is all over the place from 30 psi to 80 psi. Is there anything else it could be besides the cam being out of time with the crank?