Engine Trouble Clanking Noise

klasm

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Just got this Zeda-80, put it together following some reputable videos, started it up, tuned the carb, and ever since it had ran smooth. Went 6 miles with zero maintenance and surprised myself. I noticed a clinking noise that soon became the only thing i heard when i started it up. I have taken it apart multiple times, looked through the top and and it all looks clean. (as it should for <15 miles). I assume the sound is either something in the top end, or vibrations caused by me not putting rubber vibration dampeners in between the engine and frame. I’m not sure if it’s the piston hitting the head, because there is no pitting on either the top of the piston or the head. I have attached an idle video where you can hear it clearly, and a revving video as well. Just want to make sure the thing is safe before I ride it more. Thanks all!
Idle
Revving video
 

klasm

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It's possible the sound is completely normal as well, but I've not heard it in any videos of Motorized Bikes that I've watched.
 

Chainlube

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Is your exhaust pipe touching the frame? Sounds to run fine though.
 

Chainlube

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Now that you have a few miles on it, check your head bolts. Make sure they are tight.
 

klasm

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Now that you have a few miles on it, check your head bolts. Make sure they are tight.
I've taken it apart multiple times and replaced the acorn nuts with lock washers and normal nuts and torqued them down equally. I did that to check inside the cylinder walls and make sure the piston wasn't hitting the head, also there was a very small leak on the aluminum head gasket which I've since solved. (that was all before the videos were shot)
 

klasm

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A56E0DC4-6391-4BB8-9CBF-49567105A937.jpeg

I've taken it apart multiple times and replaced the acorn nuts with lock washers and normal nuts and torqued them down equally. I did that to check inside the cylinder walls and make sure the piston wasn't hitting the head, also there was a very small leak on the aluminum head gasket which I've since solved. (that was all before the videos were shot)
Here is the inside of the cylinder while I was in there. I noticed a very small scratch which goes from the top of the wall to the bottom of the exhaust port. It’s super thin but you can feel it with a finger. I doubt this has anything in correlation to the noise but I wanted to see if it is worth looking into. It has never ran without 2 stroke oil and my best guess is some debris got in there somehow.
 

Wrench

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With these chinesium aluminum heads
It's not the nut's that are coming loose, the aluminum is shrinking under the torqued down nuts
When the aluminum shrinks under the nut's it makes it seem like the nuts backed off and came loose
So a few re torques are needed
 

klasm

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With these chinesium aluminum heads
It's not the nut's that are coming loose, the aluminum is shrinking under the torqued down nuts
When the aluminum shrinks under the nut's it makes it seem like the nuts backed off and came loose
So a few re torques are needed
Thanks for sharing that, I'll definitely tighten it down next time I ride it.
 

DieselTech

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Just got this Zeda-80, put it together following some reputable videos, started it up, tuned the carb, and ever since it had ran smooth. Went 6 miles with zero maintenance and surprised myself. I noticed a clinking noise that soon became the only thing i heard when i started it up. I have taken it apart multiple times, looked through the top and and it all looks clean. (as it should for <15 miles). I assume the sound is either something in the top end, or vibrations caused by me not putting rubber vibration dampeners in between the engine and frame. I’m not sure if it’s the piston hitting the head, because there is no pitting on either the top of the piston or the head. I have attached an idle video where you can hear it clearly, and a revving video as well. Just want to make sure the thing is safe before I ride it more. Thanks all!
Idle
Revving video
You dont have a wrist pin bearing trying to come apart do you? If you have head off, that might be worth checking.
 
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