[Mr. Freeman1]

Hello all,

I have completed my rebuild of my Nighthawk 700s, at least I thought. Whenever it fires up and runs it makes this horrible noise, almost like the timing chain is scraping against something or is loose and is flying out and hitting something. However I took the chain tensioner out and it looks fine, spring works, everything is where it should be, but the sound continues... I included a file which I recorded the sound its quite audible around the 5 second mark...

Can anyone tell me what this would be from, and potentially how to fix it? I would really appreciate it

THE SOUND: https:// drive. google. com/file/d/1_cgWa3UIElgVNeFo8MAWsbvdmSSzUyMU/view?usp=sharing

^^^^ I had to include spaces between:// and drive. and drive. google and google. com because reasons, so please remove the spaces when pasting it into your web browser!

 

[cmonSTART]

Yikes! Hmm.. sure does sound like a chain somewhere.

Does it make any difference whether the clutch is in or out?

 

[Mr. Freeman1]

Thanks for the reply! But no the clutch makes no difference, the only thing that does make a difference would be engine speed.

 

[WintrSol]

It does have a chain-like sound to it. Sounds are hard to diagnose from recordings, though. It could be leaking header gaskets, too.
Where were you holding the microphone?

When my CB450 sounded kind of like that, it was the starter clutch coming loose.

 

[cmonSTART]

Ya.. had the same thought about the starter clutch,.

 

[Mr. Freeman1]

That would really suck if it were the starter clutch... I was holding the mic to the top front of the engine. It might be the cam chain tensioner spring for, after further investigating, my spring seems to be sticking out farther than most, as if its not seated properly. I will, again, tear the engine apart tomorrow and try to conclude my investigations :/.

I will post my results as well.