What happened to my engine?
 

I was mowing this morning when the engine started rocking & knocking. It will run with the throttle wide open only, but doesn' sound good, still rocking and knocking. I can engage the PTO and put her in gear. The deck turns and the tractor will move, but the engine is still rocking and knocking. I removed the air filter and have small dropplets of gas coming out the carb. I managed to drive her home, rocking and knocking stayed the same, didn't get any worse.
Any ideas what's going on here?

Just checked the carb. Both screws are still in the choke and throttle shafts.

Tractor has set 5 hours. Just started it. Throttle response is normal up to 1/2 throttle. Above 1/2 throttle, the knock comes back and is the worse @ WOT.

Papaw, have you rechecked the oil level? Fuel getting to the carb? How's the spark looking?

If it were mine I would not try to run it till the problem is found. If it is something inside the engine you could kill an only sick engine.

Yup, it sounds like you are fixin' to blow it up. I'd likely either 1) run it till it blows or 2) take it apart now and see if the damage is minimal. It all depends on the size of your checkbook.

Check the condenser.

I have a video of the engine running. If you think you can help figure out the problem, e mail me and I'll send the video.
Thanks
cdlongjr@msn.com

Engine is out, oil pan off. No internal damage that I can see. While pulling the engine, I found that the point wire, wire terminal had seperated at the eye portion. I can only assume that it was making contact at low rpmks and vibrating, losing contact and regaining contact, @ hi rpms. Note the piston about 7 o'clock. Seemds to be worn down. The head gasket was also blown. Shook the ciol bracket and air cleaner base so hard they both cracked.

I had the same thing happen on my 1450.It rocked and knocked and then just quit.I actually thought it blew up.Took the head off,nothing wrong there,took the oil pan off,nothing wrong there.After much head-scratching,I found that the wire attaching to the points had broken off at the terminal where it attaches to the points.I fixed that,de-carboned the head,piston and valves,put it back together with new gaskets,and much to my satisfaction,it ran great!What a relief!!!!

I'm hoping to do the same thing, but the piston worries me.

Got the deck, head, piston and valves cleaned up. I figure on replacing the piston and rod, all iginition components, rebuilding the carb & lapping the valves.
Thoughts?