The engine has always run well except it blew a head gasket,after rebuilding heads it ran perfectly for some time.All at once it started sounding funny and had no power.I figured out that the cam jumped a tooth so replaced the cam and made sure no valves where damaged.It ran perfect for a week or so ,now it is poping occasionally out exhaust.I found that one plug wire had a short.After fixing this problem it continues to pop under load or idling,I think the ignition control module is advancing the timing all the time , not only when RPMs are increased.Has anyone else had a problem with these advance modules?
All of the above,It almost must be the timing advance module.The compression is 150 on both cylinders,do you know what the timing should be,than I could test it.
