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Discussion Starter #1
I have been getting close to finally getting my CX500 running, but upon switching my plugs and cleaning the carbs well, my left cylinder is making a nasty sound, followed by my right carb pouring out gasoline. Below there is a video of the sounds it was making. Does anybody have any idea what this could be? I've been doing some research and my guess was a push rod, but they didn't look damaged when I opened up the cylinder.

Thanks in advance!

Video Here
 

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Connor, after listening to you video, and reading what you did before the rattle showed up, it really sounds like something has fallen into the spark plug hole or the intake runner and is being bounced around on top of the piston and hitting the head or valves. Don't run the motor anymore till you you inspect that possibility. Pull the spark plug and see if the gap is smaller. And look through the hole to see if there are any shinny spots on top of the piston. If so, you need to pull that head off.

The leaking carb issue is due to a totally different problem. Ignore that till you verify the noise on top of the piston.
 

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Discussion Starter #3
Connor, after listening to you video, and reading what you did before the rattle showed up, it really sounds like something has fallen into the spark plug hole or the intake runner and is being bounced around on top of the piston and hitting the head or valves. Don't run the motor anymore till you you inspect that possibility. Pull the spark plug and see if the gap is smaller. And look through the hole to see if there are any shinny spots on top of the piston. If so, you need to pull that head off.

The leaking carb issue is due to a totally different problem. Ignore that till you verify the noise on top of the piston.
Alright so I pulled off the cylinder head and found nothing. The push rods were fine, and beyond some pretty hefty carbon buildup, the valves seem fine too. Anything else this could be?
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Discussion Starter #4
I also can't be sure, but I found this bit when I took the cylinder head off, any ideas if its a part or maybe just the scrap that was causing the problem?
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Discussion Starter #6
Was that in the cylinder, or under the valve cover?
Is it open a the other end?
I'm not sure where it was, I put the whole cylinder head in a bag too keep it off the floor and when I shook the bag a little I heard it at the bottom. Its not open, just a solid piece of what I think is aluminum.
 

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Discussion Starter #8
It wouldn't have been stuck to the underside of the head, so I assume it would have been with the rockers. It doesn't look familiar to me.
The only thing I see that it looks anything like in my Clymer is the rocker arm shaft. But I took a look and they both are intact. Maybe just a coincidence?
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Look inside the intake runner/port and see if it was bouncing around on the intake valves. The piece is too big to fall past the valves when they opened.
 

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Discussion Starter #10
Look inside the intake runner/port and see if it was bouncing around on the intake valves. The piece is too big to fall past the valves when they opened.
Looked inside, both looked untouched. If it was bouncing around in there then whatever it's made of must be much too soft to do any damage (thankfully).
 

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I'd considered that, but it appears to be filled. :unsure:
Thats what I thought too, I can't think of any solid dowels like that that are made in such a short size. Also there is the possibility that it is a completely alien object that was never meant to be there. In that case my search is just for curiosity
 

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Discussion Starter #19
Good call never noticed those two little plugs til I looked at my spare engine. They look to be the right size?
What is it that they are? I'm a little confused still. Are they just meant to plug up holes while the engine is not in use?
 
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