Was wondering if any can help me with this.. I have an lt1000 tractor with a 17hp briggs intek single OHV. I got the tractor used, and dont know much about the maintence history. The engine starts right up and runs great, but when you idle it, there is a noticable knocking sound. I figured it was probably rod knock, so I removed the engine and replaced the rod, rings and gaskets. I also cleaned all the carbon off the head and piston, lapped the valves and re-adjusted them. I put it all back together and the noise is still there. I tried running the engine off the tractor and it makes the sound, so its nothing something on the craftsman doing it. I measured the crank and it is within spec according to my briggs book. What else can it be? I am thinking the balancer, but didn't notice any play in it. Thanks!