Kevin
If the mule drive/mower subframe is on that 1250, push on, or put some pressure on, the rear of the mule drive bracket where it slips over the shoulder bolts in the frame. The bracket will sometime vibrate at about that engine speed, and it sounds like a rod clatter. I had it happen on my 800, and it took me a long time to find the source of the noise, and then I found it by accident. Also had a 1200 do the same thing.
If the mule drive/mower subframe is on that 1250, push on, or put some pressure on, the rear of the mule drive bracket where it slips over the shoulder bolts in the frame. The bracket will sometime vibrate at about that engine speed, and it sounds like a rod clatter. I had it happen on my 800, and it took me a long time to find the source of the noise, and then I found it by accident. Also had a 1200 do the same thing.