knocking noise
 

Just got my 129 back together and mowed with it today. Motor was rebuilt with new rod, piston, rings, valves and gaskets. Its making a knocking sound from the front of the engine.The person who rebuilt it said it was the pto rattling. An d that it was put back together a long time ago with out anti rattle springs. Can the pto make that kind of noise. Or is he making excuses.

Yes, it can. Take it off and see if it's still doing it. If it is, I'd suspect that perhaps the cam endplay is excessive.