cb125 engine noise

[cwf23]

Hi, I am new to do the ton and decided to join after receiving a 1974 cb125. I managed to get it running after who knows how many years of sitting. There is a very loud rattling coming from the engine and I was wondering if anyone might know what the cause may be. Thanks, Craig

https://www.youtube.com/watch?v=11-pZFS6nFI&feature=youtu.be

 

[crazypj]

Sounds like valves were adjusted on overlap instead of compression

 

[cwf23]

Thank you for your reply. I also failed to mention that when I try to adjust the cam chain it does nothing. Could that be an issue as well?

 

[xb33bsa]

you can tell if the cam chain is loose by putting a wrench on the crank and gently rocking it back and forth a few degrees
observe the cam end while doing this

 

[crazypj]

On left side of engine behind cylinder is a 14mm head bolt with a 10mm head bolt screwed into it. Hold the 14mm to prevent it turning and remove the 10mm bolt. The end of adjuster push-rod is threaded 3mm. You need to feel if it's moving when you try and adjust chain tensioner lock.
If it's moving up and down with engine running the lock bolt isn't locking things in place. If it is moving,you have to raise it up and re-set lock bolt/screw under left cover. It's t least 35 yrs since I did one (damn I'm getting old :'( )