Topic: '76 CB550F knocking/pinging

[myrmidonjuan]

So I did it...I pulled the trigger on a bike.  I picked up a '76 CB550F.  

I definitely don't know much about all of this so I'm just going to reiterate what my friend was telling me.

Yeah we pulled in the clutch lever and apparently it ruled out the clutch basket.

It definitely does it at idle...I wanna say at lower idles. It goes away when it's given power, but it pretty much starts up when letting off the throttle.


Are these possible issues? Found them from some comments on a video of some other guy's bike.

you my friend have a knocking cam... thats not too good. but i'd have to hear it... anyway you may need a new camshaft and top end. but i dont really know.

SILVERHORSE347 (9 months ago)  +1    Reply | Spam
Could just be your timing chain needing adjusted, that is more likely than a bad cam.

hurracanethunder (3 months ago)  +1    Reply | Spam
probably cam chain /tensioner
and check float levels and float bowls /clean fuel tap etc

Here's the issue:

Can anyone give a possible diagnoses by watching these videos?  

[Hasenkopf]

a number of things will do that.   idle speed too low...timing...   

[myrmidonjuan]

a number of things will do that.   idle speed too low...timing...   

I definitely don't know much about all of this so I'm just going to reiterate what my friend was telling me.

Yeah we pulled in the clutch lever and apparently it ruled out the clutch basket.

It definitely does it at idle.  It goes away when it's given gas, but it pretty much starts up when we let off the throttle.

[Spanner 1]

Put-on a stout pair of gloves and ' yank ' on the header pipes close to the motor while running....any difference in sound? Seems like a header/motor leak maybe?... OR blown head gasket?, can ya feel any blow around the gasket ( not that kind!).

[myrmidonjuan]

Put-on a stout pair of gloves and ' yank ' on the header pipes close to the motor while running....any difference in sound? Seems like a header/motor leak maybe?

I'll try that.  Although, I'm positive I have a leaky head gasket.  In fact, I could see tiny little bubbles of oil around an area of the seal.

[myrmidonjuan]

Put-on a stout pair of gloves and ' yank ' on the header pipes close to the motor while running....any difference in sound? Seems like a header/motor leak maybe?... OR blown head gasket?, can ya feel any blow around the gasket ( not that kind!).

I don't know any other kind! bahhaha

Seriously though, what do you mean by blow? Some air coming from the gasket? I saw tiny bubbles.

[Spanner 1]

For def. no 'bubbles' @ the head gasket!....but more so, any leak@head/head pipes?

[TwoTired]

Can you feel the ticking at the valve adjustment caps?

If you use about 2 Ft of aquarium tubing in you ear canal, can you isolate where the noise is coming from by using the other end as your probe"

If you truly suspect a blown head gasket, a compression test should confirm.