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I just cracked open my crankcase and found a nice mix of broken piston ring at the bottom. I fished them out, but the picture shows the general condition.
I recently did what I thought was an adequate top rebuild with new rings, cam tensioner and guide, valve lapping and general cleaning.
On firing it up, I quickly heard a lovely metallic scraping inside and I knew something was wrong.
So I opened up the crankcase and found the broken pieces of ring(s)?- I need to pull the head and check the damage.

But it is a pretty straightforward procedure and I'm not sure what went wrong. I broke the glaze inside the cylinder with a hone and installed the rings correctly. I did not use a ring compressor and they seemed to go in well. The rings were not top of the line Honda, but it was a reputable eBay source.

I'm just looking to tighten up the procedure when I do it again. My future plan would not include breaking a second set and fishing out of my re-cracked crankcase.
 

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Oh bummer. What model bike?
Which ring broke? Oil?
You didn't notice any signs of binding or hesitation while rotating the engine after you lowered the cylinders?
 

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I don't understand how the broken rings could have got from the pistons into the crankcase, once the cylinders were fully in place. Not without damage to the piston or cylinder walls.

I wonder if the bottom ring(s) got broken and dropped out just as the cylinder was lowered into place. Were any of the rings still in place on the pistons.

Here's the critical stage of the procedure:

DSCF2674.jpg
 

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My guess would be that the rings were broken as the barrels were lowered
onto the block and fell un-noticed into the crankcase.
 

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The broken pieces could have fallen out of the pistons when the cylinder was removed. Really hard to say why. Most breakage occurs when the cylinder is installed
 
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