I removed the head this afternoon after troubleshooting a high end knock. Here are a few pictures . I hope , its been a long time...

Are those piston pieces? bob

that's interesting.
if you look at my for sale pics, you'll see mine.
This a d3400?
except mine had pb blaster sitting in them for a year...

Looks likw you had a ring failure and the pieces finally caused the top land of the piston to give way and what you see is mostly pieces of the ring.

Those are pieces of your top ring...it's been broken so long the pieces worked their way out on top of the piston. When they come out, they make a pretty good noise for a while, then get embedded, noise kinda quiets down until the next chunk comes up...When you get it out, it'll be what I call an "ant farm" piston...the grooves will be completely eaten away.

Yea that looks like pieces of rings to me also. I have to admit , I been rebuilding engines for a good while but , this is the first time I have seen this.
I have seen over fueling results . I have seen what excessive ether use will do. but not this.. Here is what I was told !!!!
I am working on this D2 for a friend and he said the rain cap would hang open every so often and he forgot to check it after a day of operation.
I ask how long was it left open ? He swears it was open for only about 2 weeks before he seen it. He did tell me he knows it rained for at least 3 to 4 days with it left open..
He did try to start it and it did lock and did not want to turn over. SO !! What did he do ???
He told me he kept on forcing the pony clutch with the compression release open till it finely turned over and he started it.
When it started , the old girl had a bad knock and a miss... He shut it down and sent it to me. Been sitting in my yard for a year till finely had time to get to it...
Do yall think water caused this ??? Could be .
I will get around to pulling the belly pan and oil pan later. I will post more pictures after I have piston assembly on table...

Here's what they are talking about, "Ant Farm" pistons. I think is was posted first by cc jersey.



Kelly

Hydraulic lock.
You might get away with a new to you piston a set of rings and a valve or 2.
Worse case is a new liner and maybe a rod and bearings.
Unless they are all damaged which I would not think.
Is this a D3400 engine?
Looks like it but I am not as expierenced as the rest here.
But I have pulled the pistons and liners from a D4400 without removing the pan.
Regards Chris

That's a D311 engine.

The difference in the D311 and the D315 or D4400 is the connecting rod won't come out through the sleeve on the small engine. So it's hard to remove a piston without dropping the pan. I have heard you can push the piston up far enough to remove the wrist pin and then bring the rod back down and out the bottom. Not sure if that is so. Seems unlikely to me. Much simpler to remove the equalizer spring and drop the pan for better access.