The engine has had an quality head rebuild and a new head gasket, new valve cover gasket, new plugs & wires and new points. also new T belt and tensioner. Timing is on and firing order is correct. Dwell is on too. Unfortunately I have not been able to get her to run smoothly at a higher idle. She has twin SOLEX carbs that are very well cleaned, Gas filter is new too. I will try replacing the ROTOR CAP. Could there be other issues that make for a backfiring, hard high idle? She starts well at any temp but a bit rough at first/cold. No choke for this engine. I have to pump the throtle to get good results until she warms. I am getting some oil leaks where I had none before. Does a newly rebuilt head increase compression to such an extent that seals around the big pully (top gear was replaced) leak? I do not think an AQ151 C has a traditional flame trap, but what about a breather box? Sorry for no pics. I sure could use some ideas! gjwalsh@aol.com